Hard carbon is a high-performance anode material for Li-ion battery.Precursors are synthesized using resorcinol and formaldehyde solutions as raw materials.Three kinds of hollow hard carbon spheres material(HCS-700,HCS-800 and HCS-900)are prepared at different sintering temperatures(700℃,800℃and 900℃).Structure analysis and low temperature lithium storage performance tests are conducted for these materials.Among the three kinds of hard carbon material,HCS-800 has larger specific surface area and appropriate pore size.The initial specific discharge capacity of HCS-800 anode is 104 mAh/g at-20℃and a current of 0.2 A/g in 0-3 V,and it is 93 mAh/g at the 100th cycle,which are higher than those of HCS-700 and HCS-900 anodes.The cyclic voltammetry test results show that the pseudocapacitive lithium storage contribution of HCS-800 anodes at-20℃is 78.13%,which is the highest among the three kinds of hard carbon anode.
关键词
硬碳/赝电容机制/低温/锂离子电池/电化学性能
Key words
hard carbon/pseudocapacitive mechanism/low temperature/Li-ion battery/electrochemical performance