Preparation and electrochemical characteristics of nanoscale Li₂MnSiO₄ cathode material by high pressure hydrothermal method

Abstract

Li2MnSiO4 cathode material for lithium ion batteries was successfully synthesized using a high pressure hydrothermal method.The influences of pressure, reaction temperature and precursor concentration on the preparation of Li2MnSiO4 were carefully studied. The structure, morphology and electrochemical properties of the samples were characterized and analyzed using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electrochemical test. The results show that well crystallized Li2MnSiO4 with high-purity material can be synthesized at high pressure. Moreover, higher precursor concentration is conducive to the formation of nanoscale particles of Li2MnSiO4. Electrochemical performance tests show that carbon-coated Li2MnSiO4/C composite has higher specific capacity than that of Li2MnSiO4.An initial specific discharge capacity of 178.6mAh·g-1 can be achieved for the Li2MnSiO4/C cathode material at 0.1C (the current density is 33.3mA·g-1) and a capacity retention of 97.1mAh·g-1 after 50 cycles is 54.4%. At the same time, Li2MnSiO4/C also shows smaller charge transfer resistance and higher lithium ion diffusion coefficient than that of Li2MnSiO4.

Keywords

• lithium-ion battery
• cathode material
• li₂mnsio₄
• high pressure hydrothermal method
• com-posite