The first viable large scale fuel cell systems were the liquid electrolyte alkaline fuel cells developed by Francis Bacon. Until recently the entire space shuttle fleet was powered by such fuel cells. The main difficulties with these fuel cells surrounded the liquid electrolyte, which was difficult to immobilise and suffers from problems due to the formation of low solubility carbonate species. Subsequent material developments led to the introduction of proton-exchange membranes (PEMs e.g. Nafion(r)) and the development of the well-known PEMFC. Cost is a major inhibitor to commercial uptake of PEMFCs and is localised on 3 critical components: (1) Pt catalysts (loadings still high despite considerable R&D); (2) the PEMs; and (3) bipolar plate materials (there are few inexpensive materials which survive contact with Nafion, a superacid). Water balance within PEMFCs is difficult to optimise due to electro-osmotic drag. Finally, PEM-based direct methanol fuel cells (DMFCs) exhibit reduced performances due to migration of methanol to the cathode (voltage losses and wasted fuel).Recent advances in materials science and chemistry has allowed the production of membrane materials and ionomers which would allow the development of the alkaline-equivalent to PEMs. The application of these alkaline anion-exchange membranes (AAEMs) promises a quantum leap in fuel cell viability. The applicant team contains the world-leaders in the development of this innovative technology. Such fuel cells (conduction of OH- anions rather than protons) offer a number of significant advantages:(1) Catalysis of fuel cell reactions is faster under alkaline conditions than acidic conditions - indeed non-platinum catalysts perform very favourably in this environment e.g. Ag for oxygen reduction.(2) Many more materials show corrosion resistance in alkaline than in acid environments. This increases the number and chemistry of materials which can be used (including cheap, easy stamped and thin metal bipolar plate materials).(3) Non-fluorinated ionomers are feasible and promise significant membrane cost reductions.(4) Water and ionic transport within the OH-anion conducting electrolytes is favourable electroosmotic drag transports water away from the cathode (preventing flooding on the cathode, a major issue with PEMFCs and DMFCs). This process also mitigates the 'crossover' problem in DMFCs.This research programme involves the development of a suite of materials and technology necessary to implement the alkaline polymer electrolyte membrane fuel cells (APEMFC). This research will be performed by a consortium of world leading materials scientists, chemists and engineers, based at Imperial College London, Cranfield University, University of Newcastle and the University of Surrey. This team, which represents one of the best that can be assembled to undertake such research, embodies a multiscale understanding on experimental and theoretical levels of all aspects of fuel cell systems, from fundamental electrocatalysis to the stack level, including diagnostic approaches to assess those systems. The research groups have already explored some aspects of APEMFCs and this project will undertake the development of each aspect of the new technology in an integrated, multi-pronged approach whilst communicating their ongoing results to the members of a club of relevant industrial partners. The extensive opportunities for discipline hopping and international-level collaborations will be fully embraced. The overall aim is to develop membrane materials, catalysts and ionomers for APEMFCs and to construct and operate such fuel cells utilising platinum-free electrocatalysts. The proposed programme of work is adventurous: however, risks have been carefully assessed alongside suitable mitigation strategies (the high risk components promise high returns but have few dependencies). Success will lead to the U.K. pioneering a new class of clean energy conversion technology.

Given the unprecedented demand for mobile capacity beyond that available from the RF spectrum, it is natural to consider the infrared and visible light spectrum for future terrestrial wireless systems. Wireless systems using these parts of the electromagnetic spectrum could be classified as nmWave wireless communications system in relation to mmWave radio systems and both are being standardised in current 5G systems. TOWS, therefore, will provide a technically logical pathway to ensure that wireless systems are future-proof and that they can deliver the capacities that future data intensive services such as high definition (HD) video streaming, augmented reality, virtual reality and mixed reality will demand. Light based wireless communication systems will not be in competition with RF communications, but instead these systems follow a trend that has been witnessed in cellular communications over the last 30 years. Light based wireless communications simply adds new capacity - the available spectrum is 2600 times the RF spectrum. 6G and beyond promise increased wireless capacity to accommodate this growth in traffic in an increasingly congested spectrum, however action is required now to ensure UK leadership of the fast moving 6G field. Optical wireless (OW) opens new spectral bands with a bandwidth exceeding 540 THz using simple sources and detectors and can be simpler than cellular and WiFi with a significantly larger spectrum. It is the best choice of spectrum beyond millimetre waves, where unlike the THz spectrum (the other possible choice), OW avoids complex sources and detectors and has good indoor channel conditions. Optical signals, when used indoors, are confined to the environment in which they originate, which offers added security at the physical layer and the ability to re-use wavelengths in adjacent rooms, thus radically increasing capacity. Our vision is to develop and experimentally demonstrate multiuser Terabit/s optical wireless systems that offer capacities at least two orders of magnitude higher than the current planned 5G optical and radio wireless systems, with a roadmap to wireless systems that can offer up to four orders of magnitude higher capacity. There are four features of the proposed system which make possible such unprecedented capacities to enable this disruptive advance. Firstly, unlike visible light communications (VLC), we will exploit the infrared spectrum, this providing a solution to the light dimming problem associated with VLC, eliminating uplink VLC glare and thus supporting bidirectional communications. Secondly, to make possible much greater transmission capacities and multi-user, multi-cell operation, we will introduce a new type of LED-like steerable laser diode array, which does not suffer from the speckle impairments of conventional laser diodes while ensuring ultrahigh speed performance. Thirdly, with the added capacity, we will develop native OW multi-user systems to share the resources, these being adaptively directional to allow full coverage with reduced user and inter-cell interference and finally incorporate RF systems to allow seamless transition and facilitate overall network control, in essence to introduce software defined radio to optical wireless. This means that OW multi-user systems can readily be designed to allow very high aggregate capacities as beams can be controlled in a compact manner. We will develop advanced inter-cell coding and handover for our optical multi-user systems, this also allowing seamless handover with radio systems when required such as for resilience. We believe that this work, though challenging, is feasible as it will leverage existing skills and research within the consortium, which includes excellence in OW link design, advanced coding and modulation, optimised algorithms for front-haul and back-haul networking, expertise in surface emitting laser design and single photon avalanche detectors for ultra-sensitive detection.

Energy storage is a tremendous research focus of our time and plays a vital role in tackling climate change and enabling a low carbon economy. It is the technology that will accelerate the transition to electric vehicles and facilitate the efficient utilisation of renewable energy in the grid scale applications. Today's massive production of Li-ion batteries (LIBs) has resulted in the supply risk of Li and Co, which would place future UK battery industry subject to external market and geopolitical forces. There is an immediate need to exempt from the over-reliance on LIBs through developing the next generation batteries that are based on earth-abundant elements. K-ion batteries (KIBs) offer cost-effectiveness and environmental sustainability, as they are based on K (2.09% abundance in the earth's crust, vs. 0.002% Li) and a Co-free system. KIBs possess the advantages of K having the closest reduction potential to Li (-2.92 V vs. -3.04 V) and being able to reversibly intercalate into graphite, which makes it possible to achieve high energy density and directly utilise the existing LIB manufacturing facilities. In practical applications such as grid-level storage where considerations of cell weight and size take a back seat to cost-per-kWh, KIBs represent a very attractive candidate. Building on our previous work on KIBs, our ambition is to develop high-performance KIBs and unlock the potential of KIBs as the next generation batteries. The major challenge of developing KIBs is the large size of K-ion because it causes kinetic difficulties to store K-ion. This project presents the design of electrode materials' structural defects, in accordance with the time scales of K-ion kinetics, to achieve high performance of KIBs. We will study crystalline structures that have directional pathways for K-ion insertion and diffusion at a long-range time scale, which allows to achieve high energy density. More importantly, we will investigate the approach of creating oxygen vacancies that allows a fast K-ion knetics at a short-range time scale and therefore a high power density. Simultaneously, developing KIBs requires the understanding of the complex processes occurring within the electrodes. We will perform materials characterisation and chemical analysis to understand the benefits of oxygen vacancies, especially the spatial effect of the vacancies, and acquire much-needed clarity on the fundamental chemistry of reversible K-ion storage, which is important as the development of KIBs is still in its infancy. This will suggest promising avenues for the improvement of KIB electrode materials in a wide range and generate the knowledge that could be transferred to other energy applications. The novelty in the approach is fundamentally different from the previous considerations of enhancing charge transport in the field of KIBs. The project includes the following: (i) Explore titanium niobium oxides (TNOs) as a new type of KIB anodes to reversibly store K-ion, which will identify promising materials put through as the model materials for the design of OVs. (ii) Create and control oxygen vacancies located in the surface or towards the bulk of TNOs and investigate the spatial effect of the vacancies on the enhancement of electrode power density. (iii) Perform in-situ and ex-situ characterisations of anodes with and without oxygen vacancies to best characterise, understand and explain the K-ion kinetics upon the designed structural engineering. (iv) Demonstrate KIB full-cell prototypes in a lab scale based on the advantages of performance, low-cost and environmental sustainability of the anodes (TNOs) developed in the project and the state-of-the-art cathodes (Prussian blue analogues). (v) Engage with all stakeholders in the UK's battery industry and be an advocate for KIBs.

The first viable large scale fuel cell systems were the liquid electrolyte alkaline fuel cells developed by Francis Bacon. Until recently the entire space shuttle fleet was powered by such fuel cells. The main difficulties with these fuel cells surrounded the liquid electrolyte, which was difficult to immobilise and suffers from problems due to the formation of low solubility carbonate species. Subsequent material developments led to the introduction of proton-exchange membranes (PEMs e.g. Nafion(r)) and the development of the well-known PEMFC. Cost is a major inhibitor to commercial uptake of PEMFCs and is localised on 3 critical components: (1) Pt catalysts (loadings still high despite considerable R&D); (2) the PEMs; and (3) bipolar plate materials (there are few inexpensive materials which survive contact with Nafion, a superacid). Water balance within PEMFCs is difficult to optimise due to electro-osmotic drag. Finally, PEM-based direct methanol fuel cells (DMFCs) exhibit reduced performances due to migration of methanol to the cathode (voltage losses and wasted fuel).Recent advances in materials science and chemistry has allowed the production of membrane materials and ionomers which would allow the development of the alkaline-equivalent to PEMs. The application of these alkaline anion-exchange membranes (AAEMs) promises a quantum leap in fuel cell viability. The applicant team contains the world-leaders in the development of this innovative technology. Such fuel cells (conduction of OH- anions rather than protons) offer a number of significant advantages:(1) Catalysis of fuel cell reactions is faster under alkaline conditions than acidic conditions - indeed non-platinum catalysts perform very favourably in this environment e.g. Ag for oxygen reduction.(2) Many more materials show corrosion resistance in alkaline than in acid environments. This increases the number and chemistry of materials which can be used (including cheap, easy stamped and thin metal bipolar plate materials).(3) Non-fluorinated ionomers are feasible and promise significant membrane cost reductions.(4) Water and ionic transport within the OH-anion conducting electrolytes is favourable electroosmotic drag transports water away from the cathode (preventing flooding on the cathode, a major issue with PEMFCs and DMFCs). This process also mitigates the 'crossover' problem in DMFCs.This research programme involves the development of a suite of materials and technology necessary to implement the alkaline polymer electrolyte membrane fuel cells (APEMFC). This research will be performed by a consortium of world leading materials scientists, chemists and engineers, based at Imperial College London, Cranfield University, University of Newcastle and the University of Surrey. This team, which represents one of the best that can be assembled to undertake such research, embodies a multiscale understanding on experimental and theoretical levels of all aspects of fuel cell systems, from fundamental electrocatalysis to the stack level, including diagnostic approaches to assess those systems. The research groups have already explored some aspects of APEMFCs and this project will undertake the development of each aspect of the new technology in an integrated, multi-pronged approach whilst communicating their ongoing results to the members of a club of relevant industrial partners. The extensive opportunities for discipline hopping and international-level collaborations will be fully embraced. The overall aim is to develop membrane materials, catalysts and ionomers for APEMFCs and to construct and operate such fuel cells utilising platinum-free electrocatalysts. The proposed programme of work is adventurous: however, risks have been carefully assessed alongside suitable mitigation strategies (the high risk components promise high returns but have few dependencies). Success will lead to the U.K. pioneering a new class of clean energy conversion technology.

Tides, planetary waves and gravity waves play major roles in establishing the thermal structure and general circulation of the mesosphere/lower thermosphere (MLT) region of the atmosphere (70 - 120 km). For example, the summer mesopause region is the coldest place in the atmosphere due to the meridional circulation induced by gravity wave dissipation. Less well known and understood are the equally important roles that waves play in vertical constituent transport, which is a fundamental atmospheric process that has profound effects on the chemistry and composition of the atmosphere below the turbopause at around 105 km. Atmospheric gravity waves are generated by a variety of mechanisms (e.g. orographic forcing, convection, wind shears) in the troposphere and stratosphere. As the waves propagate upwards their amplitudes grow because of the exponentially falling air pressure, causing a fraction of the waves to become superadiabatic and "break". Wave-breaking is the main source of turbulence in the MLT. A final fraction of the wave spectrum can survive and penetrate into the thermosphere. Waves, and the turbulence they generate, contribute to vertical constituent transport by inducing large-scale advection, eddy transport through turbulent mixing, dynamical transport associated with dissipating, non-breaking waves and chemical transport associated with perturbed chemistry. Recently, compelling evidence has emerged that dynamical and chemical transport is significantly underestimated in global chemistry-climate models. The vertical fluxes of Na and Fe atoms, produced from ablating meteors, have recently been measured by the ground-based lidar technique and are 5 to 10 times larger than in a state-of-the-art climate model. The higher fluxes are supported by astronomical models of dust evolution in the solar system. There is also a significant deficit in the modelled concentrations of O atoms and O3 in the MLT. The most likely reason for these apparent model deficiencies is that a fraction of the gravity wave spectrum is not explicitly captured in models because the wavelengths are smaller than the model horizontal grid-scale (typically > 100 km), and these small waves make a major contribution to vertical transport. The computational cost of increasing the horizontal resolution to include small-scale wave transport effects directly in global models - especially incorporating chemistry - is currently prohibitive. The aim of the WAVECHASM project is to produce a parameterization which can be used to calculate all components of vertical transport in a global model. The project will proceed in four stages. First, we will run a global model with the facility to increase the horizontal resolution regionally down to ~ 14 km, in order to demonstrate the importance of short wavelength waves. In the second step we will parameterise a recent mathematical treatment of dynamical and chemical transport, which shows that these transport terms can be computed in a relatively straightforward way from the wave spectrum in each model grid box. For the third stage we will assemble a data-base of measurements of the vertical fluxes of Na, Fe (in some cases) and heat at 6 lidar stations, the Na density at 16 stations, and satellite measurements of Na and other MLT constituents (e.g. O, O3, NOx, CO2). In the final stage, the new global model with wave transport will be run for 20 years (covering the period of these observations), to study the impact of wave transport on the global distribution and seasonal variations of the important, chemically active species. Once the vertical flux of Na atoms can be reconciled with the abundance of Na in the layer around 90 km, we will obtain an accurate estimate of the amount of interplanetary dust entering the atmosphere, and thus constrain astronomical models of dust evolution in the solar system and improve our understanding the impacts of this dust throughout the atmosphere.