Imperial College London

Professor Nigel Brandon OBE FREng FRS

Faculty of Engineering

Dean of the Faculty of Engineering
 
 
 
//

Contact

 

+44 (0)20 7594 8600n.brandon Website

 
 
//

Location

 

2.06Faculty BuildingSouth Kensington Campus

//

Summary

 

Publications

Publication Type
Year
to

479 results found

Stettler MEJ, Woo M, Ainalis D, Achurra-Gonzalez P, Speirs J, Cooper J, Lim DH, Brandon N, Hawkes Aet al., 2023, Review of Well-to-Wheel lifecycle emissions of liquefied natural gas heavy goods vehicles, Applied Energy, Vol: 333, ISSN: 0306-2619

It has been suggested that using liquefied natural gas as a fuel source for heavy goods vehicles could provide a reduction in greenhouse gas emissions. Various studies have investigated different aspects of the lifecycle emissions of natural gas heavy goods vehicles throughout the past decade, however, there has been little comparative analysis across these studies. This review provides a comprehensive examination of the well-to-wheel lifecycle emissions of liquefied natural gas for heavy goods vehicles in comparison to diesel, the current standard. A systematic selection criteria based on relevance to the defined well-to-wheel system boundary of liquefied natural gas as a fuel source for heavy goods vehicles, including greenhouse gas emissions, were augmented by the authors knowledge of the field. The various data are categorised by engine technology and model year (pre- and post-2015), average speed of the duty cycle, and then statistically analysed to identify clear trends and correlations in the emissions produced. The two primary factors affecting the well-to-wheel greenhouse gas emissions of natural gas heavy hoods vehicles are: (i) natural gas engine fuel efficiency relative to diesel, and (ii) methane leakage across the supply chain. Methane leakage rates are a significant uncertainty and range from 0.3 to 20 % of throughput. With long-term perspective of efficiency penalty (10 %) in natural gas engines, the well-to-wheel greenhouse gas emissions reduction of natural gas fuelled trucks against diesel is up to 10 %, which appears insufficient toward net zero emissions by 2050. The use of biomethane further reduces the greenhouse gas emissions by 34–66 % depending on the engine technology. Controlling fugitive methane emissions in the fuel production and supply chain remains critical.

Journal article

Wang A, Tan R, Liu D, Lu J, Wei X, Alvarez-Fernandez A, Ye C, Breakwell C, Guldin S, Kucernak AR, Jelfs KE, Brandon NP, McKeown NB, Song Qet al., 2023, Ion-selective Microporous Polymer Membranes with Hydrogen-bond and Salt-bridge Networks for Aqueous Organic Redox Flow Batteries., Adv Mater

Redox flow batteries (RFBs) have great potential for long-duration grid-scale energy storage. Ion conducting membranes are a crucial component in RFBs, allowing charge-carrying ions to transport while preventing the cross-mixing of redox couples. Commercial Nafion membranes are widely used in RFBs, but their unsatisfactory ionic and molecular selectivity as well as high costs limit the performance and the widespread deployment of this technology. To extend the longevity and reduce the cost of RFB systems, inexpensive ion-selective membranes are highly desired that concurrently deliver low ionic resistance and high selectivity towards redox-active species. In this work, high-performance RFB membranes are fabricated from blends of carboxylate- and amidoxime-functionalized polymers of intrinsic microporosity (PIMs) that exploit the beneficial properties of both polymers. The enthalpy-driven formation of cohesive interchain interactions, including hydrogen bonds and salt bridges, facilitates the microscopic miscibility of the blends, while ionizable functional groups within the sub-nanometer pores allow optimization of membrane ion transport functions. The resulting microporous membranes demonstrate fast cation conduction with low crossover of redox-active molecular species, enabling improved power ratings and reduced capacity fade in aqueous RFBs using anthraquinone and ferrocyanide as redox couples. This article is protected by copyright. All rights reserved.

Journal article

Pan Y, Wang H, Brandon NP, 2022, A fast two-phase non-isothermal reduced-order model for accelerating PEM fuel cell design development, International Journal of Hydrogen Energy, Vol: 47, Pages: 38774-38792, ISSN: 0360-3199

A reduced-order model (ROM) is developed for proton exchange membrane fuel cells (PEMFCs) considering the non-isothermal two-phase effects, with the goal of enhancing computational efficiency and thus accelerating fuel cell design development. Using analytical order reduction and approximation methods, the fluxes and source terms in conventional 1D conservation equations are reduced to six computing nodes at the interfaces between each cell component. The errors associated with order reduction are minimized by introducing new approximation methods for the potential distribution, the transport properties, and the membrane hydration status. The trade-off between model accuracy and computational efficiency is studied by comparing the simulation results and computational times of the new model with a full 1D model. The new model is nearly two orders of magnitude faster without sacrificing too much accuracy (<4% difference) compared to the 1D model. The new model is then used to analyze the influence of the membrane electrode assembly (MEA) design on cell performance and internal state distributions, offering insights into MEA structural optimization. The model can be readily extended to account for more detailed physico-chemical processes, such as Knudsen diffusion or the influence of micro-porous layers, and it can be an effective tool for understanding and designing PEMFCs.

Journal article

Yang S, Zhou C, Wang Q, Chen B, Zhao Y, Guo B, Zhang Z, Gao X, Chowdhury R, Wang H, Lai C, Brandon NP, Wu B, Liu Xet al., 2022, Highly‐aligned ultra‐thick gel‐based cathodes unlocking ultra‐high energy density batteries, Energy & Environmental Materials, Vol: 5, Pages: 1332-1339, ISSN: 2575-0356

Increasing electrode thickness can substantially enhance the specific energy of lithium-ion batteries, however ionic transport, electronic conductivity and ink rheology are current barriers to adoption. Here a novel approach using a mixed xanthan gum and locust bean gum binder to construct ultra-thick electrodes is proposed to address above issues. After combining aqueous binder with single walled carbon nanotubes (SWCNT), active material (LiNi0.8Co0.1Mn0.1O2) and subsequent vacuum freeze drying, highly-aligned and low tortuosity structures with a porosity of ca. 50% can be achieved with an average pore size of 10 μm, whereby the gum binder-SWCNT-NMC811 forms vertical structures supported by tissue-like binder/SWCNT networks allowing for excellent electronic conducting phase percolation. As a result, ultra-thick electrodes with a mass loading of about 511 mg·cm-2 and 99.5 wt% active materials have been demonstrated with a remarkable areal capacity of 79.3 mAh·cm−2, which is the highest value reported so far. This represents a >25x improvement compared to conventional electrodes with an areal capacity of about 3 mAh·cm-2. This route also can be expanded to other electrode materials, such as LiFePO4 and Li4Ti5O12, and thus opens the possibility for low-cost and sustainable ultra-thick electrodes with increased specific energy for future lithium-ion batteries.

Journal article

Ye C, Tan R, Wang A, Chen J, Comesaña Gándara B, Breakwell C, Alvarez-Fernandez A, Fan Z, Weng J, Bezzu CG, Guldin S, Brandon N, Kucernak A, Jelfs K, McKeown N, Song Qet al., 2022, Long-life aqueous organic redox flow batteries enabled by amidoxime-functionalized ion-selective polymer membranes, Angewandte Chemie International Edition, Vol: 61, ISSN: 1433-7851

Redox flow batteries (RFBs) based on aqueous organic electrolytes are a promising technology for safe and cost-effective large-scale electrical energy storage. Membrane separators are a key component in RFBs, allowing fast conduction of charge-carrier ions but minimizing the cross-over of redox-active species. Here, we report the molecular engineering of amidoxime-functionalized polymers of intrinsic microporosity (AO-PIMs) by tuning their polymer chain topology and pore architecture to optimize membrane ion transport selectivity. AO-PIM membranes are integrated with three emerging aqueous organic flow battery chemistries, and the synergetic integration of ion-selective membranes with molecular engineered organic molecules in neutral-pH electrolytes leads to significantly enhanced cycling stability.

Journal article

Liu X, Zhang L, Yu H, Wang J, Li J, Yang K, Zhao Y, Wang H, Wu B, Brandon N, Yang Set al., 2022, Bridging multiscale characterization technologies and digital modeling to evaluate lithium battery full lifecycle, Advanced Energy Materials, Vol: 12, ISSN: 1614-6832

The safety, durability and power density of lithium-ion batteries (LIBs) are currently inadequate to satisfy the continuously growing demand of the emerging battery markets. Rapid progress has been made from material engineering to system design, combining experimental results and simulations to enhance LIB performance. Limited by spatial and temporal resolution, state-of-the-art advanced characterization techniques fail to fully reveal the complex multi-scale degradation mechanism in LIBs. Strengthening interaction and iteration between characterization and modeling improves the understanding of reaction mechanisms as well as design and management of LIBs. Herein, a seed cyber hierarchy and interactional network framework is demonstrated to evaluate the overall lifecycle of LIBs. The typical examples of bridging the characterization techniques and modeling are discussed. The critical parameters extracted from multi-scale characterization can serve as digital inputs for modeling. Furthermore, advanced computational techniques including cloud computing, big data, machine learning, and artificial intelligence can also promote the comprehensive understanding and precise control of the whole battery lifecycle. Digital twins techniques will be introduced enabling the real-time monitoring and control of LIBs, autonomous computer-assisted characterizations and intelligent manufacturing. It is anticipated that this work will provide a roadmap for further intensive research on developing high-performance LIBs and intelligent battery management.

Journal article

Qiu K, Trudgeon D, Li X, Yufit V, Chakrabarti B, Brandon N, Shah Aet al., 2022, Study of Quaternary Ammonium Additives towards High-Rate Zinc Deposition and Dissolution Cycling for Application in Zinc-Based Rechargeable Batteries, BATTERIES-BASEL, Vol: 8

Journal article

Zhao Y, Ouyang M, Wang Y, Qin R, Zhang H, Pan W, Leung DYC, Wu B, Liu X, Brandon N, Xuan J, Pan F, Wang Het al., 2022, Biomimetic lipid-bilayer anode protection for long lifetime aqueous zinc-metal batteries, Advanced Functional Materials, Vol: 32, ISSN: 1616-301X

The practical application of rechargeable aqueous zinc batteries is impeded by dendrite growth, especially at high areal capacities and high current densities. Here, this challenge is addressed by proposing zinc perfluoro(2-ethoxyethane)sulfonic (Zn(PES)2) as a zinc battery electrolyte. This new amphipathic zinc salt, with a hydrophobic perfluorinated tail, can form an anode protecting layer, in situ, with a biomimetic lipid-bilayer structure. The layer limits the anode contact with free H2O and offers fast Zn2+ transport pathways, thereby effectively suppressing dendrite growth while maintaining high rate capability. A stable, Zn2+-conductive fluorinated solid electrolyte interphase (SEI) is also formed, further enhancing zinc reversibility. The electrolyte enables unprecedented cycling stability with dendrite-free zinc plating/stripping over 1600 h at 1 mA cm−2 at 2 mAh cm−2, and over 380 h under an even harsher condition of 2.5 mA cm−2 and 5 mAh cm−2. Full cell tests with a high-loading VS2 cathode demonstrate good capacity retention of 78% after 1000 cycles at 1.5 mA cm−2. The idea of in situ formation of a biomimetic lipid-bilayer anode protecting layer and fluorinated SEI opens a new route for engineering the electrode–electrolyte interface toward next-generation aqueous zinc batteries with long lifetime and high areal capacities.

Journal article

Fan L, Li C, Aravind PV, Cai W, Han M, Brandon Net al., 2022, Methane reforming in solid oxide fuel cells: Challenges and strategies, JOURNAL OF POWER SOURCES, Vol: 538, ISSN: 0378-7753

Journal article

Long X, Boldrin P, Zhang Y, Brandon N, Paterson N, Millan Met al., 2022, Towards integrated gasification and fuel cell operation with carbon capture: Impact of fuel gas on anode materials, Fuel, Vol: 318, ISSN: 0016-2361

Integrated gasification fuel cell technology is a promising option for processing solid fuels, which would enable high efficiencies to be reached in small-scale power generation. Among the different fuel cell types, solid oxide fuel cells present a good temperature match with fluidised bed gasification as well as greater versatility in terms of the fuel gas composition they can handle. However, their resistance to impurities in the gas needs to be addressed. The main objective of this work is to assess the impact on typical materials used in fuel cell anodes of the gases produced from a gasifier operating with a N2-free gasification agent, which would make the system carbon-capture ready. A laboratory scale continuous pressurised fluidised bed reactor has been modified to study CO2 and steam (concentration up to 40 mol%.) gasification of lignite at 850 °C. A second stage fixed bed reactor has been specially designed and constructed to study degradation of two SOFC anode materials (nickel/yttrium–stabilised zirconium oxide (Ni/YSZ) and nickel/gadolinium-doped ceria (Ni/CGO)) after exposure to real fuel gas at 765 °C. Under these conditions, which did not involve any gas cleaning/conditioning between stages, carbon deposition on the surface of anode materials was much smaller than in previous studies that used model tar compounds as feeds. Fuel gas from CO2/H2O gasification tended to deposit less carbon and sulphur on tested anode materials, particularly on Ni/CGO, than that from CO2 gasification. The anode materials converted a significant fraction of the fed tar to gas.

Journal article

Ye C, Wang A, Breakwell C, Tan R, Bezzu G, Hunter-Sellars E, Williams D, Brandon N, Klusener P, Kucernak A, Jelfs K, McKeown N, Song Qet al., 2022, Development of efficient aqueous organic redox flow batteries using ion-sieving sulfonated polymer membranes, Nature Communications, Vol: 13, ISSN: 2041-1723

Redox flow batteries using aqueous organic-based electrolytes are promising candidates for developing cost-effective grid-scale energy storage devices. However, a significant drawback of these batteries is the cross-mixing of active species through the membrane, which causes battery performance degradation. To overcome this issue, here we report size-selective ion-exchange membranes prepared by sulfonation of a spirobifluorene-based microporous polymer and demonstrate their efficient ion sieving functions in flow batteries. The spirobifluorene unit allows control over the degree of sulfonation to optimize the transport of cations, whilst the microporous structure inhibits the crossover of organic molecules via molecular sieving. Furthermore, the enhanced membrane selectivity mitigates the crossover-induced capacity decay whilst maintaining good ionic conductivity for aqueous electrolyte solution at pH 9, where the redox-active organic molecules show long-term stability. We also prove the boosting effect of the membranes on the energy efficiency and peak power density of the aqueous redox flow battery, which shows stable operation for about 120 h (i.e., 2100 charge-discharge cycles at 100 mA cm−2) in a laboratory-scale cell.

Journal article

Xia Y, Ouyang M, Yufit V, Tan R, Regoutz A, Wang A, Mao W, Chakrabarti B, Kavei A, Song Q, Kucernak A, Brandon Net al., 2022, A cost-effective alkaline polysulfide-air redox flow battery enabled by a dual-membrane cell architecture, Nature Communications, Vol: 13, Pages: 1-13, ISSN: 2041-1723

With the rapid development of renewable energy harvesting technologies, there is a significant demand for long-duration energy storage technologies that can be deployed at grid scale. In this regard, polysulfide-air redox flow batteries demonstrated great potential. However, the crossover of polysulfide is one significant challenge. Here, we report a stable and cost-effective alkaline-based hybrid polysulfide-air redox flow battery where a dual-membrane-structured flow cell design mitigates the sulfur crossover issue. Moreover, combining manganese/carbon catalysed air electrodes with sulfidised Ni foam polysulfide electrodes, the redox flow battery achieves a maximum power density of 5.8 mW cm-2 at 50% state of charge and 55 °C. An average round-trip energy efficiency of 40% is also achieved over 80 cycles at 1 mA cm-2. Based on the performance reported, techno-economic analyses suggested that energy and power costs of about 2.5 US$/kWh and 1600 US$/kW, respectively, has be achieved for this type of alkaline polysulfide-air redox flow battery, with significant scope for further reduction.

Journal article

Huang Y, Kang J, Liu L, Zhong X, Lin J, Xie S, Zeng Y, Shah N, Brandon N, Zhao Y, Meng Cet al., 2022, A hierarchical coupled optimization approach for dynamic simulation of building thermal environment and integrated planning of energy systems with supply and demand synergy, ENERGY CONVERSION AND MANAGEMENT, Vol: 258, ISSN: 0196-8904

Journal article

Romano MC, Antonini C, Bardow A, Bertsch V, Brandon NP, Brouwer J, Campanari S, Crema L, Dodds PE, Gardarsdottir S, Gazzani M, Kramer GJ, Lund PD, Mac Dowell N, Martelli E, Mastropasqua L, McKenna RC, Monteiro JGM-S, Paltrinieri N, Pollet BG, Reed JG, Schmidt TJ, Vente J, Wiley Det al., 2022, Comment on "How green is blue hydrogen?", ENERGY SCIENCE & ENGINEERING, Vol: 10, Pages: 1944-1954

Journal article

Li F-F, Gao J-F, He Z-H, Brandon N, Li X, Kong L-Bet al., 2022, Engineering novel Ni2-XCoxP structures for high performance lithium-ion storage, ENERGY STORAGE MATERIALS, Vol: 48, Pages: 20-34, ISSN: 2405-8297

Journal article

Li L, Wang J, Zhong X, Lin J, Wu N, Zhang Z, Meng C, Wang X, Shah N, Brandon N, Xie S, Zhao Yet al., 2022, Combined multi-objective optimization and agent-based modeling for a 100% renewable island energy system considering power-to-gas technology and extreme weather conditions, APPLIED ENERGY, Vol: 308, ISSN: 0306-2619

Journal article

Ye M, Sharp P, Brandon N, Kucernak Aet al., 2022, System-level comparison of ammonia, compressed and liquid hydrogen as fuels for polymer electrolyte fuel cell powered shipping, International Journal of Hydrogen Energy, Vol: 47, Pages: 8565-8584, ISSN: 0360-3199

With the aim to reduce emissions from marine transport, electric propulsion systems for a water taxi and container ship powered by a hydrogen polymer electrolyte membrane fuel cell system are designed and analyzed compared to the current fuel-oil engine systems in terms of system energy and exergy efficiency, fuel consumption, mass and volume, environmental impacts and cost. Hydrogen is stored either as a compressed gas (GH2), cryogenic liquid (LH2) or produced from liquid ammonia (LNH3) and can deliver 91%,91% and 88% greenhouse gas reductions, respectively. All hydrogen sources fit within ship volume and mass constraints apart from GH2 in the cargo ship. In the absence of carbon policy measures, the costs over a 25-year system life are 108% (GH2), 112% (LH2), 116% (LNH3) greater for the container ship and 43% (GH2), 105% (LNH3) greater for the water taxi. A carbon tax of £75-191/tonne CO2eq would allow the low carbon options to become cost competitive.

Journal article

Wehrle L, Wang Y, Boldrin P, Brandon NP, Deutschmann O, Banerjee Aet al., 2022, Optimizing solid oxide fuel cell performance to re-evaluate its role in the mobility sector, ACS Environmental Au, Vol: 2, Pages: 42-64, ISSN: 2694-2518

A sustainable, interconnected, and smart energy network in which hydrogen plays a major role cannot be dismissed as a utopia anymore. There are vast international and industrial ambitions to reach the envisioned system transformation, and the decarbonization of the mobility sector is a central pillar comprising a huge economic share. Solid oxide fuel cells (SOFCs) are one of the most promising technologies in the brigade of clean energy devices and have potentially wide applicability for transportation, due to their high efficiencies and impurity tolerance. To uncover future pathways to boost the cell’s performance, we propose a detailed multiscale modeling methodology to evaluate the direct impact of cell materials and morphologies on commercial-scale system performance. After acquiring intrinsic electrokinetics decoupled from mass and charge transport of different anode and cathode materials via a half-cell model, a full cell model is employed to identify the most promising electrode combination. Subsequently, a scale-up to the system level is performed by coupling a 3-D kW-stack model to the balance of plant components while focusing on morphological optimization of the membrane electrode assembly (MEA). On optimally tailoring the MEA, model results demonstrate that an advanced cell design comprising a Ni fiber-CGO matrix structured anode and a LSCF-infiltrated CGO cathode could reach a stack power density of 1.85 kW L–1 and a net system efficiency of 52.2% for operation at <700 °C, with manageable stack temperature gradients of <14 K cm–1. The model-optimized power density is substantially higher than those of commercial stacks and surpasses industrial targets for SOFC-based range extenders. Thus, with further cell and stack development targeting the performance limiting processes elucidated in the paper, commercial SOFCs could, alongside range extenders, also act as prime movers in larger scale transport applications such as trucks

Journal article

Simon BA, Gayon-Lombardo A, Pino-Muñoz CA, Wood CE, Tenny KM, Greco KV, Cooper SJ, Forner-Cuenca A, Brushett FR, Kucernak AR, Brandon NPet al., 2022, Combining electrochemical and imaging analyses to understand the effect of electrode microstructure and electrolyte properties on redox flow batteries, Applied Energy, Vol: 306, Pages: 1-22, ISSN: 0306-2619

Reducing the cost of redox flow batteries (RFBs) is critical to achieving broad commercial deployment of largescale energy storage systems. This can be addressed in a variety of ways, such as reducing component costs orimproving electrode design. The aim of this work is to better understand the relationship between electrodemicrostructure and performance. Four different commercially available carbon electrodes were examined – twocloths and two papers (from AvCarb® and Freudenberg Performance Materials) – and a comprehensive study ofthe different pore-scale and mass-transport processes is presented to elucidate their effect on the overall cellperformance. Electrochemical measurements were carried out in a non-aqueous organic flow-through RFB withthese different electrodes, using two supporting solvents (propylene carbonate and acetonitrile) and at a varietyof flow rates. Electrode samples were scanned using X-ray computed tomography, and a customised segmentation technique was employed to extract several microstructural parameters. A pore network model was used tocalculate the pressure drops and permeabilities, which were found to be within 1.26 × 10− 11 and 1.65 × 10− 11m2 for the papers and between 8.61 × 10− 11 and 10.6 × 10− 11 m2 for the cloths. A one-dimensional model wasdeveloped and fit to polarisation measurements to obtain mass-transfer coefficients, km, which were found to bebetween 1.01 × 10− 6 and 5.97 × 10− 4 m s− 1 with a subsequent discussion on Reynolds and Sherwood numbercorrelations. This work suggests that, for these fibrous materials, permeability correlates best with electrochemical cell performance. Consequently, the carbon cloths with the highest permeability and highest masstransfer coefficients, displayed better performances.

Journal article

Lin J, Wu N, Li L, Xie M, Xie S, Wang X, Brandon N, Sun Y, Chen J, Zhao Yet al., 2021, Performance and parameter optimization of a capacitive salinity/heat engine for harvesting salinity difference energy and low grade heat, RENEWABLE ENERGY, Vol: 183, Pages: 283-293, ISSN: 0960-1481

Journal article

Pan Y, Wang H, Brandon N, 2021, Gas diffusion layer degradation in proton exchange membrane fuel cells: Mechanisms, characterization techniques and modelling approaches, Journal of Power Sources, Vol: 513, ISSN: 0378-7753

Proton exchange membrane fuel cells (PEMFCs) have been considered as a promising power source for electric vehicles. However, the widespread use of PEMFCs requires a significant improvement in durability. As a key component of PEMFCs, gas diffusion layer (GDL) does not only provide a mechanical support for other fuel cell components, but also governs the mass, heat, and electron transport that directly affect cell performance. In this paper, the latest research progress of GDL durability is reviewed from three aspects: degradation mechanisms, experimental methods, and modelling approaches. The six degradation modes of GDLs, namely chemical oxidation, electrochemical carbon corrosion, freezing/thawing, mechanical degradation, material dissolution and erosion by gas flow are discussed under different cell operating conditions. Experimental techniques, including the long-term and accelerated stress tests (AST) and methods for measuring property deterioration are then introduced. Several AST protocols have been developed to decouple the above degradation modes, but few have tried to relate these tests with GDL degradation in practice. Modelling approaches relating to GDL degradation are also covered. Although various types of models have been developed for multiple purposes, a complete model from the mechanistic level to the cell performance is still missing.

Journal article

Chowdhury R, Zhao Y, Xia Y, Ouyang M, Brandon N, Banerjee Aet al., 2021, Revisiting the promise of bi-layer graded cathodes for improved Li-ion battery performance, Sustainable Energy and Fuels, Vol: 5, Pages: 5193-5204, ISSN: 2398-4902

Improving power and energy density by grading electrode microstructures is a promising topic in the field of battery electrode engineering. While previous modelling studies have predicted both considerable and marginal improvements in cell performance, very few experimental studies have been conducted to validate the performance of graded electrodes. In this article, we report on the fabrication of a bi-layer graded lithium-ion battery cathode by varying both the particle size and the porosity in each layer. Structural analyses were carried out via 2D (scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX)) and 3D (X-ray computed tomography (XCT) and focused-ion beam tomography (FIB)) imaging techniques. The bi-layer cathode (BLC) exhibits an increase of 62.8% in discharge capacity at 2C compared to a conventional single layer electrode. The polarization and electrochemical impedance spectroscopy data indicate that the improved capacity performance of the BLC can be attributed to reduced charge transfer resistance and increased solid phase diffusivity. However, capacity retention performance reveals that the BLC retained no advantage over a conventional electrode in a half-cell configuration after 100 cycles. At 1C, the BLC displayed only minimal improvement in power (4.6%) and energy (7.6%) density based on first discharge capacity. As such, noting the extra challenges involved in manufacturing such graded electrode structures, it is recommended that their use is best focused on higher C rate applications and that more work is needed to demonstrate the retention of the higher C rate performance gain over multiple cycles.

Journal article

Mac Dowell N, Sunny N, Brandon N, Herzog H, Ku AY, Maas W, Ramirez A, Reiner DM, Sant GN, Shah Net al., 2021, The hydrogen economy: A pragmatic path forward, Joule, Vol: 5, Pages: 2524-2529, ISSN: 2542-4351

For hydrogen to play a meaningful role in a sustainable energy system, all elements of the value chain must scale coherently. Advocates support electrolytic (green) hydrogen or (blue) hydrogen that relies on methane reformation with carbon capture and storage; however, efforts to definitively choose how to deliver this scaling up are premature. For blue hydrogen, methane emissions must be minimized. Best in class supply chain management in combination with high rates of CO2 capture can deliver a low carbon hydrogen product. In the case of electrolytic hydrogen, the carbon intensity of power needs to be very low for this to be a viable alternative to blue hydrogen. Until the electricity grid is deeply decarbonized, there is an opportunity cost associated with using renewable energy to produce hydrogen, as opposed to integrating this with the power system. To have a realistic chance of success, net zero transition pathways need to be formulated in a way that is coherent with socio-political-economic constraints.

Journal article

Chakrabarti BK, Kalamaras E, Ouyang M, Liu X, Remy G, Wilson PF, Williams MA, Rubio-Garcia J, Yufit V, Bree G, Hajimolana YS, Singh A, Tariq F, Low CTJ, Wu B, George C, Brandon NPet al., 2021, Trichome-like Carbon-Metal Fabrics Made of Carbon Microfibers, Carbon Nanotubes, and Fe-Based Nanoparticles as Electrodes for Regenerative Hydrogen/Vanadium Flow Cells, ACS APPLIED NANO MATERIALS, Vol: 4, Pages: 10754-10763

Journal article

Brandon NP, Parkes MA, 2021, Fuel Cells: Materials, Encyclopedia of Materials: Metals and Alloys, Pages: 377-382, ISBN: 9780128197332

Book chapter

Fan L, Mokhov A, Saadabadi SA, Brandon N, Aravind PVet al., 2021, Methane steam reforming reaction in solid oxide fuel cells: Influence of electrochemical reaction and anode thickness, JOURNAL OF POWER SOURCES, Vol: 507, ISSN: 0378-7753

Journal article

Balcombe P, Staffell I, Kerdan IG, Speirs JF, Brandon NP, Hawkes ADet al., 2021, How can LNG-fuelled ships meet decarbonisation targets? An environmental and economic analysis, Energy, Vol: 227, Pages: 1-12, ISSN: 0360-5442

International shipping faces strong challenges with new legally binding air quality regulations and a 50% decarbonisation target by 2050. Liquefied natural gas (LNG) is a widely used alternative to liquid fossil fuels, but methane emissions reduce its overall climate benefit. This study utilises new emissions measurements and supply-chain data to conduct a comprehensive environmental life cycle and cost assessment of LNG as a shipping fuel, compared to heavy fuel oil (HFO), marine diesel oil (MDO), methanol and prospective renewable fuels (hydrogen, ammonia, biogas and biomethanol). LNG gives improved air quality impacts, reduced fuel costs and moderate climate benefits compared to liquid fossil fuels, but with large variation across different LNG engine types. Methane slip from some engines is unacceptably high, whereas the best performing LNG engine offers up to 28% reduction in global warming potential when combined with the best-case LNG supply chain. Total methane emissions must be reduced to 0.8–1.6% to ensure climate benefit is realised across all timescales compared to current liquid fuels. However, it is no longer acceptable to merely match incumbent fuels; progress must be made towards decarbonisation targets. With methane emissions reduced to 0.5% of throughput, energy efficiency must increase 35% to meet a 50% decarbonisation target.

Journal article

Jiao K, Xuan J, Du Q, Bao Z, Xie B, Wang B, Zhao Y, Fan L, Wang H, Hou Z, Huo S, Brandon NP, Yin Y, Guiver MDet al., 2021, Designing the next generation of proton-exchange membrane fuel cells., Nature, Vol: 595, Pages: 361-369, ISSN: 0028-0836

With the rapid growth and development of proton-exchange membrane fuel cell (PEMFC) technology, there has been increasing demand for clean and sustainable global energy applications. Of the many device-level and infrastructure challenges that need to be overcome before wide commercialization can be realized, one of the most critical ones is increasing the PEMFC power density, and ambitious goals have been proposed globally. For example, the short- and long-term power density goals of Japan's New Energy and Industrial Technology Development Organization are 6 kilowatts per litre by 2030 and 9 kilowatts per litre by 2040, respectively. To this end, here we propose technical development directions for next-generation high-power-density PEMFCs. We present the latest ideas for improvements in the membrane electrode assembly and its components with regard to water and thermal management and materials. These concepts are expected to be implemented in next-generation PEMFCs to achieve high power density.

Journal article

Ouyang M, Bertei A, Cooper SJ, Wu Y, Boldrin P, Liu X, Kishimoto M, Wang H, Naylor Marlow M, Chen J, Chen X, Xia Y, Wu B, Brandon NPet al., 2021, Model-guided design of a high performance and durability Ni nanofiber/ceria matrix solid oxide fuel cell electrode, Journal of Energy Chemistry, Vol: 56, Pages: 98-112, ISSN: 2095-4956

Mixed ionic electronic conductors (MIECs) have attracted increasing attention as anode materials for solid oxide fuel cells (SOFCs) and they hold great promise for lowering the operation temperature of SOFCs. However, there has been a lack of understanding of the performance-limiting factors and guidelines for rational design of composite metal-MIEC electrodes. Using a newly-developed approach based on 3D-tomography and electrochemical impedance spectroscopy, here for the first time we quantify the contribution of the dual-phase boundary (DPB) relative to the three-phase boundary (TPB) reaction pathway on real MIEC electrodes. A new design strategy is developed for Ni/gadolinium doped ceria (CGO) electrodes (a typical MIEC electrode) based on the quantitative analyses and a novel Ni/CGO fiber–matrix structure is proposed and fabricated by combining electrospinning and tape-casting methods using commercial powders. With only 11.5 vol% nickel, the designer Ni/CGO fiber–matrix electrode shows 32% and 67% lower polarization resistance than a nano-Ni impregnated CGO scaffold electrode and conventional cermet electrode respectively. The results in this paper demonstrate quantitatively using real electrode structures that enhancing DPB and hydrogen kinetics are more efficient strategies to enhance electrode performance than simply increasing TPB.

Journal article

Gao X, Liu X, He R, Wang M, Xie W, Brandon N, Wu B, Ling H, Yang Set al., 2021, Designed high-performance lithium-ion battery electrodes using a novel hybrid model-data driven approach, Energy Storage Materials, Vol: 36, Pages: 435-458, ISSN: 2405-8297

Lithium-ion batteries (LIBs) have been widely recognized as the most promising energy storage technology due to their favorable power and energy densities for applications in electric vehicles (EVs) and other related functions. However, further improvements are needed which are underpinned by advances in conventional electrode designs. This paper reviews conventional and emerging electrode designs, including conventional LIB electrode modification techniques and electrode design for next-generation energy devices. Thick electrode designs with low tortuosity are the most conventional approach for energy density improvement. Chemistries such as lithium-sulfur, lithium-air and solid-state batteries show great potential, yet many challenges remain. Microscale structural modelling and macroscale functional modelling methods underpin much of the electrode design work and these efforts are summarized here. More importantly, this paper presents a novel framework for next-generation electrode design termed: Cyber Hierarchy And Interactional Network based Multiscale Electrode Design (CHAIN-MED), a hybrid solution combining model-based and data-driven techniques for optimal electrode design, which significantly shortens the development cycle. This review, therefore, provides novel insights into combining existing design approaches with multiscale models and machine learning techniques for next-generation LIB electrodes.

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00170077&limit=30&person=true