Protected Anodes for Lithium Sulphur Batteries (PALIS)

JM, Oxford University, Ilika and WMG propose a collaboration to jointly develop a high energy density protected anode material for Li-sulphur batteries, as a low cost alternative to traditional lithium-ion. The project will evaluate protection mechanisms for anode materials. Without the protective layer, anode materials show little reversible capacity. These protected anodes give a much higher cycle life that can compete with traditional LiB (~500-1000 cycles at least before 80% initial capacity is reached). This is an innovative energy storage solution to be used in conjunction with renewable energy harvesting, with around three times more energy density than the current technology. Storing electrical energy from renewable energy sources in battery banks for release at peak times has the benefit of reducing CO2 emissions. In addition, with the higher volumetric energy envisioned using this technology, LiSBs will have the potential to be used in electric vehicles which has previously been the reserve of Li-ion technology. The main advantage to using LiSBs over LIBs is the higher energy density, which can lead to lower cost per Wh. This can give LiSBs the market opportunity for implementation in future application in the stationary energy storage and automotive sector. Oxford will screen and develop solid electrolyte materials with optimum ionic conductivity for protecting the lithium anode. This work will involve synthesis of ceramic electrolytes and will be carried out in combination with the high throughput-PVD techniques of Ilika. In parallel, fabrication of composite structures of protective layers for the anode will be created in collaboration with Ilika and JM. Evaluation of best-performing solid electrolytes to be employed for protecting the anode will subsequently take place in order to focus on analysis of the protection mechanism. A deeper understanding of the interfacial phenomena, occurring in the protected anode will be further investigated through both electrochemical and microstructural analyses such as galvanostatic/potentiostatic polarisation or cycling, EIS, SEM, XPS and X-ray CT. In this project the WMG will utilise facilities and technologists within its partly government funded Energy Innovation Centre (EIC) which has been established to provide both industry and academia alike with a capability to use emerging battery chemistries in multi-scale formats from research scale through to representative prototype sizes. The EIC features electrode mixing and coating equipment incorporating the latest technology for producing high quality, consistent electrodes. JM are experts in material development and have recently demonstrated that cell performance of their cathode material in Li-S prototypes is comparable and competitive with commercial Li-ion cells in terms of cycle life, energy density and rate capability. The partners will advance the performance of current LiSBs technology by developing high energy density protected anode materials -imperative for pushing LiSBs onto both the stationary energy storage market and into the automotive industry. The WMG will work directly with JM and Ilika to develop the high energy protected anode composites and also optimise the Li-S electrodes in conjunction with Oxford for both high energy and cycle life. The aim of the research is to provide new anode and cathode materials for high energy LiSBs, which will surpass performance levels of the commercialised Li-ion graphite systems. The benefit to the academic community is the dissemination of practical research which has the capability of accelerating the uptake of LiSB technology into a high value manufacturing environment. The commercialisation strategy is to licence the Li-S technology IP to material and battery manufacturers.

Lithium-ion batteries (LIBs) are the most widely used type of rechargeable batteries in the world, offering significant advantages over other battery chemistries, such as high energy density (~600 Wh/L) and long cycle life (>1000 cycles). But, with increases in Li consumption having grown at a rate of ca. 22% per annum since 2000, future demand for LIBs is predicted to increase continuously due to their use in portable electronic devices and also in larger-scale products, such as electric vehicles and energy storage systems. The predicted global market revenue in 2020 is expected to reach around $33B. In addition, the geographical distribution throughout largely inaccessible, politically unstable countries of global Li reserves may bring about rapid rises in the price of lithium resources as the demand for rechargeable batteries grows exponentially. Lithium sulphur battery (LiSB) have gained recognition as promising candidates for next generation large scale energy storage systems thanks to recent advances in achieving promising results. Li-S shares many properties with Li as an energy storage material and hence technology transfer helps to implement the technology much faster into existing markets. Li-S systems represent a much more energy dense technology than traditional Li systems and will facilitate greater UK energy security due to potentially less demand in traditional LiBs. In order to achieve the future demand for battery technology, bringing fundamental science, core engineering and manufacturing together in a single framework of PALIS to tackle the key aspects of lithium-sulphur batteries by protecting the anode, will overcome the limitations in energy density, process manufacturing and cost effectiveness that currently hinder the existing battery market. One way of achieving this is by using high energy density cathode and anode materials. Protection of anode materials can enable implementation such high energy density materials without the intrinsic deterioration of the electrodes observed in traditional Li-S chemistries. The success of this technology would allow Li-S technology access to the automotive and grid storage industry. Societal: In a modern society where we rely more and more on renewable energy, a demand for cheap energy storage solutions have become a key issue. The ability to locally store renewable energy will significantly reduce the cost of domestic energy supply and will also enable access to energy in-situ at times of peak demand. Economic: The distributed storage market is estimated at to be ca. $17b by 2018. Manufacturing JM's Li-S batteries using high energy density anode and cathode materials within the European economic areas (EEA) is a strategy set to gain a market share and thus an opportunity to generate significant economic value for the UK. Li-S offers greater energy density compared to traditional LiBs, implying a potential cost saving provided the manufacturing process can be optimised. Having access to cheap energy storage will become ever more important. These systems would have to be cost effective over the product life, emphasizing the importance of upfront cost and cycle life. Low cost and high performance technologies will be of great interest to other inter-related market sectors, e.g. renewable energy generations (PV, wind and hydro), increasing demand further for such a device. Environmental Legislation: The EU's 20-20-20 strategy plans for a 20% drop in CO2 emissions, a 20% improvement in energy efficiency and an increase of the share of renewable energy to 20% by 2020. This project has a clear role in all of these areas. The ability to deploy new renewable technologies with energy storage solutions is highly dependent on a strong research, development and manufacturing base for effective durable batteries. IEA's Energy Technology Perspectives scenario 2DS (global temperature increase limit of 2oC) proposes that PV-derived energy is expected to save 30Gt of CO2 by 2050.