以酚醛树脂为碳源,分别采用了固相法和溶胶凝胶法合成了锂离子电池正极材料Li3V2(PO4)3/C。结果表明,高分子材料酚醛树脂是一种优良的碳源材料,其热解后得到的导电网络能够有效的提高Li3V2(PO4)3的电化学性能;两种试样的充放电曲线和交流阻抗图谱体现出了试样良好的可逆性,其极化程度很低,电荷转移电阻小;而相对于固相法来讲,溶胶凝胶法和表面活性剂CTAB(十六烷基三甲基溴化铵)的共同作用能够有效的将颗粒粒径控制在纳米级别。用这种方法合成的试样在15 C下充放电比容量也能高于90 m Ah/g,5 C倍率下循环50次比容量无衰减,证明了以酚醛树脂为碳源并采用溶胶凝胶法合成的试样具有很好的倍率性能与循环性能。
Using the phenolic resin as carbon source,two samples of the cathode material,lithium-ion batteries cathode material Li3V2( PO4)3/ C were synthesized by solid state method and sol-gel method,respectively. The results show that the carbon net formed by pyrolysized phenolic resin enhances the electrochemical performance of Li3V2( PO4)3efficiently. The charge / discharge curves and EIS pattern illustrated the good reversibility,low polarization level,low charge transfer resistance of two samples.Comparing with solid-state method,the sol-gel method with the combination of surfactant CTAB( Cetyl Trimethyl Ammonium Bromide) is benefit to control the particle size of cathode material at nano-level.The sample synthesized by this way,which was marked as LVP-2,has more outstanding rate and cycle performances than the sample synthesized by solid state method,which is marked as LVP-1. Its capacity is higher than 90 m Ah / g at 15 C and it cycled at 5 C for 50 times without any attenuation.