Cetyltrimethylammonium bromide induced generation of highly (200) planes-exposed LiMnPO4 nanosheets coated by nitrogen-doped carbon for high-performance batteries

A simple solvothermal method is designed to synthesize LiMnPO4/N-doped C composites with core-shell structure using cetyltrimethylammonium bromide (CTAB) as surfactant and nitrogen source. The effectively growth of (200) planes and nitrogen-doped carbon layer coated LiMnPO4 nanosheets are obtained. The doped nitrogen induces the generation of active defect sites, which changes the cell electronic layer structure, and improve the electronic conductivity and diffusion rate of lithium ions. Thus, the electrochemical performance is beneficial from the synergistic effect of specific planar exposure and particular interfacial modifications. The optimal sample shows the supreme electrochemical performance at 0.1C, 1C and 5C with capacities of 159.1, 122.6 and 83.1 mAh g−1, respectively. The capacity retention can achieve 98 % even after 200 cycles at 1C. This work provides a simple but effective strategy to design polyanion cathode materials with enhanced electrochemical performance.