The Department for Transport of UK government announced to ban petrol and diesel vehicles by 2030 to facilitate Net Zero strategy. Being a major part of transportation electrification, the electric vehicle (EV) market is growing quickly; there are 190,727 new registrations of pure-EVs in 2021, 76.3% increase compared to 2020. Despite such success, the driving range and fast charge capability of EVs are recognised as predominant factors limiting further market penetration. Unfortunately, the physics of these requirements results in a trade-off of the lithium-ion battery design strategy. For instance, cells with high energy density provide maximum range but cannot deliver fast charging, because thicker electrodes suffer more acutely from the concentration polarisation across the electrode due to the slow ionic transport. Likewise, cells with high power density are capable of fast charging, but suffer from low mileage. More impetus in fundamental studies on physical processes of battery and the interplay between microstructure and performance are needed to eliminate range anxiety and charge-time trauma of EVs. Graphite/silicon composite electrode is regarded as one of the most promising candidates for next-generation automotive LiBs due to its high energy density. However, it suffers from the major drawbacks such as (1) volume expansion, cracking and pulverization of Si particles; (2) fast decay of capacity due to side reactions, consuming electrolyte rapidly. There is great potential to mitigate the degradation mechanisms by improved compositional and structural design based on better understanding of the ambiguous synergistic effect between the two types of particles. Moreover, lithium plating on the graphitic negative electrode is regarded as the foremost safety concern restricting the fast charge capability, leading to the consumption of lithium, electrolyte decomposition, formation of lithium dendrite and even thermal runaway. Therefore, it is critical to suppress lithium plating employing electrode design, manufacturing and rational protocols to address the longstanding challenge of battery fast charging. In this project, we aim to develop scalable and widely applicable innovations to facilitate the advancement of battery technologies for transport electrification. Correlative in operando experiment coupling the chemical, structure, crystallographic and electrochemical information from 2D to 4D will be conducted to elucidate the failure mechanisms of the graphite/Si composite electrode at the micrometer scale, particularly the synergistic dynamics of charge transfer, lithiation and deformation. Structural evolution is characterised as a function of SOC, C-rates and Si content, and linked to the capacity decay. Advanced 3D microstructure-resolved electro-chemo-mechanical model will be developed to analyse the performance limiting mechanisms, the impact of microstructural evolution on the reaction heterogeneities and predict the cycle life; in operando experiment and 3D microstructure-resolved phase field modelling will be employed to reveal the interplay between 3D microstructure of the electrode with the phase separation phenomenon, spatial dynamics of lithiation and plating. In addition, the physical processes of the relaxation behaviour, such as lithium exchange and redistribution will be elucidated by the 3D model, which will provide valuable guidelines for the refinement of fast charge protocols in terms of the timing and period of the rest steps. Finally, building on the insights of the study above, graphite/Si composite electrodes with novel structures will be fabricated, aiming to achieve at least 280 Wh kg-1 at the cell level with 20 mins charging for 50% of the capacity, corresponding to 15% increase in energy density and over 30% decrease of charging time compared to the commercial cells; an advanced physics-based fast charge protocol will be delivered to mitigate the plating risk and capacity fade.

Energy storage is more important today than at any time in human history. It has a vital role to play in storing electricity from renewable sources (wind, wave, solar) and is key to the electrification of transport. However, current energy storage technologies are not fit for purpose. No single energy storage technology can meet the needs of all applications, but many of the research challenges to improve performance and reduce costs are common across electrochemical, mechanical and thermal devices: new materials need to be developed and tested, thermodynamic processes have to be optimized, and lab-based prototypes must be suitable for scale-up. These technologies have to be integrated into robust and cost effective systems. In response to the situation, especially within the UK context, we propose to establish a SUPERGEN Energy Storage Hub. The consortium will bring together investigators with strong international and national reputations in energy storage research and spanning the entire value chain from the energy storage technologies themselves, through manufacturing, integration, and evaluation of the whole system in which the energy storage would be embedded. The consortium will address a number of the critical barriers that face progress towards the commercialisation of energy storage and its widespread exploitation in the UK and elsewhere. Members of the consortium cover areas in which the UK has both the scientific capability and an energy system need. The activities will embrace energy policy, as well as a roadmap and a vision for energy storage research in the UK stretching into the future, thus setting the agenda for UK energy storage. Through extensive networking, including strong engagement with all stakeholders in industry, NGOs and government the hub will not only remain informed and inform others about the latest developments in energy storage it will also bring the energy storage community in the UK as a whole closer together and through wide dissemination engage the public. Through the strength of the Hub and its links will come more effective pathways for the exploitation of new research and new ideas in commercial products.

Electrical energy storage can contribute to meeting the UK's binding greenhouse emission targets by enabling low carbon transport through electric vehicles (EVs) in the expanding electric automotive industry. However, challenges persist in terms of performance, safety, durability and costs of the energy storage devices such as lithium ion batteries (LIBs). Although there has been research in developing new chemistry and advanced materials that has significantly improved electrical energy storage performance, the structure of the electrodes and LIBs and their manufacturing methods have not been changed since the 1980s. The current manufacturing methods do not allow control over the structures at the electrode and device levels, which leads to restricted ion transport during cycling. The approach of this research is to develop a complete materials-manufacture-characterisation chain for LIBs, solid-state LIBs (SSLIBs) and next generation of batteries. Novel structures at the electrode and device levels will be designed to promote fast directional ion transport, increase energy and power densities, improve safety and cycling performance and reduce costs. New, scalable manufacturing techniques will be developed to realise making the designed structures and reduce interfacial resistance in SSLIBs. Finally, state-of-the-art physical and chemical characterisation techniques including a suite of X-ray photoelectron spectroscopy (XPS), X-ray computed tomography (XCT) and electrochemical testing will be used to understand the underlining charge storage mechanism, interfacial phenomena and how electrochemical performance is influenced by structural changes of the energy storage devices. The results will subsequently be used to guide iterations of the structure design. The fabricated batteries will be packaged into pouch cells and rigorously tested by EV protocols through close collaborations with industry to ensure flexible adaptability to the current industry match to create near-term high impact in industry. The commercialisation strategy is to license developed intellectual property (IP) to material and battery manufacturers.

As the pressures of climate change becomes larger there is great interest in making highly efficient methods for generating and storing electrical energy. There is enormous interest in making batteries that exploit various lithium-based materials. These devices contain a solid anode and a solid cathode immersed in either a polymer, or solvent based electrolyte. Efficient batteries require that the thickness of both the cathode and anode materials are small in order both to reduce electrical resistance and to allow lithium to rapidly insert and de-insert itself from the solid electrode materials (by a process called intercalating). Furthermore they require that the surface area of the interface between the electrolyte and the anode (and cathode) should be made as large as possible in order to give sufficient lithium intercalation to allow practical levels of charging and discharging. As a result of these requirements batteries are currently designed with a nanostructured anode (and cathode) made either in a organised manner or by pressing grains together. Understanding how such nanostructures should be optimised in order to maximise energy efficiency is a major challenge. This is further complicated by the fact that the solid materials expand significantly (up to three times) when lithium is intercalated during charge and discharge of the battery creating both mechanical deformations and changes in the electrochemical behaviour of the surfaces. In order for such designs to be understood, and to be optimised, requires mathematical models to be developed and analysed that account for the critical properties of the nanostructure, the intercalation processes and the electrical properties of the materials. To replace existing high-efficiency high-cost silicon based solar cells there is significant interest in developing inexpensive polymer-based, and dye-sensitised, solar cells.Design of solar cells may seem unconnected from batteries but there is considerable similarity in the physical processes, mathematical models and geometry of the nanostructure of both these devices which provide the opportunity for a concerted theoretical program of research with significant technology transfer. Both types of solar cell that we consider here consist of two materials with different electrochemical properties separated by an interface (in the case of a dye-sensitised solar cell this interface is coated with a photo-absorbing dye monolayer). Efficient solar absorbtion requires that the interface between the two main materials is as large as possible while maintaining good electrical conduction. Nanostrucutred materials are being explored in order to meet these requirements. In order to optimise solar cell design models are required that account for solar absorbtion, the complex geometry of the nanostructure and charge transportation in the materials and across the interface.The purpose of this proposal is to develop novel mathematical techniques and models motivated by and closely aligned to practical developments in the complex nanostructure of these electrochemical systems. By analysing such models the most important mechanisms and features of the devices in determining their efficiency will be explored and identified.

As the pressures of climate change becomes larger there is great interest in making highly efficient methods for generating and storing electrical energy. There is enormous interest in making batteries that exploit various lithium-based materials. These devices contain a solid anode and a solid cathode immersed in either a polymer, or solvent based electrolyte. Efficient batteries require that the thickness of both the cathode and anode materials are small in order both to reduce electrical resistance and to allow lithium to rapidly insert and de-insert itself from the solid electrode materials (by a process called intercalating). Furthermore they require that the surface area of the interface between the electrolyte and the anode (and cathode) should be made as large as possible in order to give sufficient lithium intercalation to allow practical levels of charging and discharging. As a result of these requirements batteries are currently designed with a nanostructured anode (and cathode) made either in a organised manner or by pressing grains together. Understanding how such nanostructures should be optimised in order to maximise energy efficiency is a major challenge. This is further complicated by the fact that the solid materials expand significantly (up to three times) when lithium is intercalated during charge and discharge of the battery creating both mechanical deformations and changes in the electrochemical behaviour of the surfaces. In order for such designs to be understood, and to be optimised, requires mathematical models to be developed and analysed that account for the critical properties of the nanostructure, the intercalation processes and the electrical properties of the materials. To replace existing high-efficiency high-cost silicon based solar cells there is significant interest in developing inexpensive polymer-based, and dye-sensitised, solar cells.Design of solar cells may seem unconnected from batteries but there is considerable similarity in the physical processes, mathematical models and geometry of the nanostructure of both these devices which provide the opportunity for a concerted theoretical program of research with significant technology transfer. Both types of solar cell that we consider here consist of two materials with different electrochemical properties separated by an interface (in the case of a dye-sensitised solar cell this interface is coated with a photo-absorbing dye monolayer). Efficient solar absorbtion requires that the interface between the two main materials is as large as possible while maintaining good electrical conduction. Nanostrucutred materials are being explored in order to meet these requirements. In order to optimise solar cell design models are required that account for solar absorbtion, the complex geometry of the nanostructure and charge transportation in the materials and across the interface.The purpose of this proposal is to develop novel mathematical techniques and models motivated by and closely aligned to practical developments in the complex nanostructure of these electrochemical systems. By analysing such models the most important mechanisms and features of the devices in determining their efficiency will be explored and identified.