Synthesis Of LiFePO₄ And LiNi_1/3Co_1/3Mn_1/3O₂ Cathode Materials With Liquid Crystal As Structure Directing Agent And The Researches Of Their Performance

We have developed a new method to synthesis LiFePO4 (LFP) and LiNi1/3Co1/3Mn1/3O2 using cholesteric benzoate as structure-directing agent. A carambola-like LFP is prepared, which consists of LFP thin layers with significantly shortened [010] channel of ～15 nm with selectively exposed (020) plane. The unique structure greatly promotes the Li+ diffusion along the preferential direction for Li storage, bringing an unprecedented Li+ diffusion coefficient of 8.31×10-9 cm2 s-1. On the other hand, we have successfully coated a highly-conductive unltrathin carbon layer with controllable thickness (～1.5 nm) onto the surface of LiFePO4 sheets, enabling fast electron transportation along the two-dimensional sheet. With the structural advantages of both components, a hierarchically mixed conducting network is formed, and the composite exhibits stable and extremely fast kinetics upon Li storage, which promises its use for high-power batteries with long lifespan. The composite exhibits stable and extremely fast electrochemistry upon Li storage by delivering almost a theoretical capacity (167 mA h g-1) at 0.1 C and ～50% of the theoretical capacity (82 mA h g-1) at a high rate of 20 C, and exhibits stable cycling performances at different rates.Interconnection grid nanostructured LiNi1/3Co1/3Mn1/3O2 cathode material with a selectively exposed{010} facet is prepared using liquid crystal structure directing method. Interconnection grid nanostructured LiNi1/3Co1/3Mn1/3O2 exhibits stable and extremely fast kinetics for Li storage. The unique structure greatly promotes the Li+ diffusion along the preferential direction for Li storage. And according to the EIS result, the Rct of interconnection grid nanostructured LiNi1/3Co1/3Mn1/3O2 is 74Ω which means better electron conductive. Interconnection grid nanostructured LiNi1/3Co1/3Mn1/3O2 exhibits stable and extremely fast electrochemistry upon Li storage by delivering high discharge capacity (185 mA h g-1) at 0.1 C and ～50% of the theoretical capacity (127 mA h g-1) at a high rate of 10 C, and exhibits stable cycling performances at different rates.In view of its favorable electrochemical performances, the composite material may find its use in LIBs with stable cyclability and high energy output for emerging EV applications. The strategy is simple, yet effective, and can bring inspirations to those working on high-energy batteries. All these will contribute to a better economic sustainability to benefit the whole industry.