Imperial College London

Professor Nigel Brandon OBE FREng FRS

Faculty of Engineering

Dean of the Faculty of Engineering
 
 
 
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Contact

 

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

 
 
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Location

 

2.06Faculty BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

462 results found

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

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

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, ISSN: 2041-1723

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

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

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

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., 2021, Highly‐aligned ultra‐thick gel‐based cathodes unlocking ultra‐high energy density batteries, Energy & Environmental Materials, 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

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

Trudgeon DP, Loh A, Ullah H, Li X, Yufit V, Brandon N, Liu M, Kong Let al., 2021, The influence of zinc electrode substrate, electrolyte flow rate and current density on zinc-nickel flow cell performance, ELECTROCHIMICA ACTA, Vol: 373, ISSN: 0013-4686

Journal article

Chowdhury R, Banerjee A, Zhao Y, Liu X, Brandon Net al., 2021, Simulation of bi-layer cathode materials with experimentally validated parameters to improve ion diffusion and discharge capacity, Sustainable Energy and Fuels, Vol: 5, Pages: 1103-1119, ISSN: 2398-4902

The prospect of thick graded electrodes for both higher energy and higher-power densities in lithium-ion batteries is investigated. The simulation results discussed in previous reports on next-generation graded electrodes do not recognize the effect of material processing conditions on microstructural, transport and kinetic parameters. Hence, in this work, we focus on the effect of material processing conditions on particle morphology and its subsequent influence on microstructure (porosity and tortuosity), along with the resultant transport (solid-phase diffusivity) and kinetic (reaction rate constant) properties of synthesized single-layer cathodes. These experimental insights are employed to simulate the benefits of 400 μm thick bi-layer graded cathodes with two different particle sizes and porosities in each layer. The microstructural, transport, and kinetic information are obtained through 3D imaging and electrochemical impedance spectroscopy (EIS) techniques. These parameters are used to develop bi-layer numerical models to understand transport phenomena and to predict cell performance with such graded structures. Simulation results highlight that bi-layer cathodes display higher electrode utilization (solid phase lithiation) next to the current-collector compared to conventional monolayer cathodes with an increase of 39.2% in first discharge capacity at 2C. Additionally, the simulations indicate that an improvement of 47.7% in energy density, alongside a marginal increase of 0.6% in power density, can be achieved at 4C by structuring the porosity in the layer next to the separator to be higher than the porosity in the layer next to the current-collector.

Journal article

Liu X, Qian X, Tang W, Luo H, Zhao Y, Tan R, Qiao M, Gao X, Hua Y, Wang H, Zhao S, Lai C, Titirici M, Brandon N, Yang S, Wu Bet al., 2021, Designer uniform Li plating/stripping through lithium–cobalt alloying hierarchical scaffolds for scalable high-performance lithium-metal anodes, Journal of Energy Chemistry, Vol: 52, Pages: 385-392, ISSN: 2095-4956

Lithium metal anodes are of great interest for advanced high-energy density batteries such as lithium-air, lithium-sulfur and solid-state batteries, due to their low electrode potential and ultra-high theoretical capacity. There are, however, several challenges limiting their practical applications, which include low coulombic efficiency, the uncontrollable growth of dendrites and poor rate capability. Here, a rational design of 3D structured lithium metal anodes comprising of in-situ growth of cobalt-decorated nitrogen-doped carbon nanotubes on continuous carbon nanofibers is demonstrated via electrospinning. The porous and free-standing scaffold can enhance the tolerance to stresses resulting from the intrinsic volume change during Li plating/stripping, delivering a significant boost in both charge/discharge rates and stable cycling performance. A binary Co-Li alloying phase was generated at the initial discharge process, creating more active sites for the Li nucleation and uniform deposition. Characterization and density functional theory calculations show that the conductive and uniformly distributed cobalt-decorated carbon nanotubes with hierarchical structure can effectively reduce the local current density and more easily absorb Li atoms, leading to more uniform Li nucleation during plating. The current work presents an advance on scalable and cost-effective strategies for novel electrode materials with 3D hierarchical microstructures and mechanical flexibility for lithium metal anodes.

Journal article

Jamil Z, Ruiz-Trejo E, Brandon NP, 2021, Electrochemical Performance of Electrodeposited Ni/GDC Anodes for Solid Oxide Fuel Cells, ASM Science Journal, Vol: 14, Pages: 148-154, ISSN: 1823-6782

The fabrication of SOFC anodes using infiltration method has shown a potential to produce an excellent anode performance with a relatively reduced amount of nickel. Nonetheless, infiltration method is very challenging for industrial application due to its lengthy and energy consuming process, which involves repeated Ni nitrate solution infiltration, heating and cooling cycles. A combination of electroless and electrodeposition technique has shown a promising alternative method due to its ability to accelerate the Ni adding process into porous scaffolds at near-room or room temperature. Ni loadings range between ~5 to ~18 vol% were deposited onto the GDC scaffolds to demonstrate the catalytic role of Ni loadings on the electrochemical performance of the electrodeposited anodes. The total electrode polarisation of the anodes exhibited a promising result when the loading of Ni 5.3 vol% (0.74 Ω.cm2). Further, increases in Ni loadings to 17.6 vol% Ni, relatively decreased the performance of the electrode to 1.25 Ω.cm2

Journal article

Chakrabarti BK, Feng J, Kalamaras E, Rubio-Garcia J, George C, Luo H, Xia Y, Yufit V, Titirici M-M, Low CTJ, Kucernak A, Brandon NPet al., 2020, Hybrid redox flow cells with enhanced electrochemical performance via binderless and electrophoretically deposited nitrogen-doped graphene on carbon paper electrodes., ACS Applied Materials and Interfaces, Vol: 12, Pages: 53869-53878, ISSN: 1944-8244

Hybrid redox flow cells (HRFC) are key enablers for the development of reliable large-scale energy storage systems; however, their high cost, limited cycle performance, and incompatibilities associated with the commonly used carbon-based electrodes undermine HRFC's commercial viability. While this is often linked to lack of suitable electrocatalytic materials capable of coping with HRFC electrode processes, the combinatory use of nanocarbon additives and carbon paper electrodes holds new promise. Here, by coupling electrophoretically deposited nitrogen-doped graphene (N-G) with carbon electrodes, their surprisingly beneficial effects on three types of HRFCs, namely, hydrogen/vanadium (RHVFC), hydrogen/manganese (RHMnFC), and polysulfide/air (S-Air), are revealed. RHVFCs offer efficiencies over 70% at a current density of 150 mA cm-2 and an energy density of 45 Wh L-1 at 50 mA cm-2, while RHMnFCs achieve a 30% increase in energy efficiency (at 100 mA cm-2). The S-Air cell records an exchange current density of 4.4 × 10-2 mA cm-2, a 3-fold improvement of kinetics compared to the bare carbon paper electrode. We also present cost of storage at system level compared to the standard all-vanadium redox flow batteries. These figures-of-merit can incentivize the design, optimization, and adoption of high-performance HRFCs for successful grid-scale or renewable energy storage market penetration.

Journal article

Chen J, Ouyang M, Boldrin P, Atkinson A, Brandon NPet al., 2020, Understanding the coarsening and degradation in a nanoscale nickel gadolinia-doped-ceria electrode for high-temperature applications., ACS Applied Materials and Interfaces, Vol: 12, Pages: 47564-47573, ISSN: 1944-8244

Nanostructure engineering is an effective approach to enhance the electrochemical performance of energy devices. While the high surface area of nanoparticles greatly enlarges the density of reaction sites, it often also leads to relatively rapid degradation as the particles tend to coarsen to reduce their high surface energy. Therefore, a nickel/gadolinia-doped-ceria (CGO) cermet electrode is studied, with a novel porous nanostructure consisting of nanoscale Ni (100 nm) and CGO (50 nm) crystallites, cosintered from nanocomposite precursor agglomerate particles. This electrode combines both high performance and excellent durability, with a total area-specific resistance (ASR) of 0.11 Ω cm2 at 800 °C and a stable ASR with up to 170 h ageing in humidified 5% H2-N2. Post-test analysis by 3D tomography shows that nickel coarsens and is responsible for the initial increase in ASR. However, the subsequent electrochemical performance is stable because reaction at the double phase boundaries (DPBs) on the surfaces of nanoscale CGO becomes dominant and is resistant to ageing. At this stage, the coarsened Ni network is also stabilized by the surrounding nanostructure. The dominant role of the DPB reaction is supported quantitatively using a continuum model with geometrical parameters obtained from 3D tomography.

Journal article

Strbac G, Pudjianto D, Aunedi M, Djapic P, Teng F, Zhang X, Ameli H, Moreira R, Brandon Net al., 2020, Role and value of flexibility in facilitating cost-effective energy system decarbonisation, Progress in Energy, Vol: 2, Pages: 042001-042001

<jats:title>Abstract</jats:title> <jats:p>Decarbonisation of the electricity system requires significant and continued investment in low-carbon energy sources and electrification of the heat and transport sectors. With diminishing output and shorter operating hours of conventional large-scale fossil fuel generators, there is a growing need and opportunity for other emerging technologies to provide flexibility in the context of grid support, balancing, security services, and investment options to support a cost-effective transition to a lower-carbon energy system. This article summarises the key findings from a range of studies investigating the potential benefits and challenges associated with the future low-carbon energy system. The key challenges associated with balancing local, national and regional objectives to minimise the overall cost of decarbonising the future energy system are also discussed. Furthermore, the paper highlights the importance of cross-energy vector flexibility, and coordination across electricity, heat, and gas systems which is critical for shaping the future low-carbon energy systems. Although most of the case studies presented in this article are based on the UK, and to some extent the EU decarbonisation pathways, the overall conclusions regarding the value of flexibility are relevant for the global energy transition.</jats:p>

Journal article

Loh A, Li X, Taiwo OO, Tariq F, Brandon NP, Wang P, Xu K, Wang Bet al., 2020, Development of Ni-Fe based ternary metal hydroxides as highly efficient oxygen evolution catalysts in AEM water electrolysis for hydrogen production, INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, Vol: 45, Pages: 24232-24247, ISSN: 0360-3199

Journal article

Liu X, Ouyang M, Orzech M, Niu Y, Tang W, Chen J, Naylor Marlow M, Puhan D, Zhao Y, Tan R, Brankin C, Haworth N, Zhao S, Wang H, Childs P, Margadonna S, Wagemaker M, Pan F, Brandon N, George C, Wu Bet al., 2020, In-situ fabrication of carbon-metal fabrics as freestanding electrodes for high-performance flexible energy storage devices, Energy Storage Materials, Vol: 30, Pages: 329-336, ISSN: 2405-8297

Hierarchical 1D carbon structures are attractive due to their mechanical, chemical and electrochemical properties however the synthesis of these materials can be costly and complicated. Here, through the combination of inexpensive acetylacetonate salts of Ni, Co and Fe with a solution of polyacrylonitrile (PAN), self-assembling carbon-metal fabrics (CMFs) containing unique 1D hierarchical structures can be created via easy and low-cost heat treatment without the need for costly catalyst deposition nor a dangerous hydrocarbon atmosphere. Microscopic and spectroscopic measurements show that the CMFs form through the decomposition and exsolution of metal nanoparticle domains which then catalyze the formation of carbon nanotubes through the decomposition by-products of the PAN. These weakly bound nanoparticles form structures similar to trichomes found in plants, with a combination of base-growth, tip-growth and peapod-like structures, where the metal domain exhibits a core(graphitic)-shell(disorder) carbon coating where the thickness is in-line with the metal-carbon binding energy. These CMFs were used as a cathode in a flexible zinc-air battery which exhibited superior performance to pure electrospun carbon fibers, with their metallic nanoparticle domains acting as bifunctional catalysts. This work therefore unlocks a potentially new category of composite metal-carbon fiber based structures for energy storage applications and beyond.

Journal article

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