Hierarchical 3D micro/nanostructured LiMn1-xFexPO4/graphene hybrid composite for high power Li-ion battery and its dynamic study by in-situ X-ray absorption and THz spectroscopies

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Lithium ion batteries (LIBs) represent an important family of energy storage devices due to their high voltage, high energy density, and good cycling stability. However, as a power source for electric vehicles (EVs) and hybrid EVs, the current LIB technology still needs to be further advanced to improve their power density. ** This Strategic project aims to develop new type of high-performance and cheap cathode materials for high-power and safe LIBs. We propose to focus on one of the most promising cathode materials, i.e. LiMn1-xFexPO4 (LMFP), which provides up to 20% increase in energy density compared with the well-developed LiFePO4. This could offer Canadian cell manufacturers with a competitive advantage by allowing energy storage systems to weigh less and require fewer cells. However, LMFP does have its own challenges, including (i) poor electronic conductivity, and (ii) sluggish Li+ diffusion. Further, deep understanding of the dynamics of Li+ ions and electrons in this new LMFP cathode material is lacking. ** In this project, we will employ nanotechnology to develop a novel hierarchical 3D micro/nanostructured LMFP with graphene coating cathode materials, targeting to solve the above challenges. Equally important is the application of novel terahertz (THz) and synchrotron radiation techniques, and theoretical modeling, to perform unique in situ and ex situ studies of the Li+ and electron dynamics. This would provide significant guidance to design super performance LMFP/graphene cathode materials, giving Canadian companies in the energy sector a competitive advantage. Particularly, THz spectroscopy is a non-contact electrical probe that can measure charge dynamics and photoconductivity on sub-picosecond to nanosecond timescales (temporal resolutions that traditional methods do not have). This would help to make LIBs safe and economically competitive with today's internal combustion engine for EVs. The applicants will work with three Canadian industrial partners for applications in sectors of high socio-economic impact to Canada.********