环己苯和三乙胺对锂离子蓄电池的过充保护

Aplication of cyclohexyl benzene and triethyl amine for overcharge protection of Li-ion batteries

用循环伏安、充放电仪、扫描电子显微镜(SEM)等方法研究了环己苯和三乙胺对锂离子蓄电池的过充保护作用以及对电池综合电性能的影响。研究表明,环己苯在4.7V(vs.Li/Li+)发生电聚合反应,生成导电聚合物膜聚环己苯使电池自放电至安全状态,防止了电池的过充;三乙胺与氢质子反应,不但提高了电池的过充能力,而且有效地抑制了电池的膨胀;环己苯与三乙胺的联合应用可使方型锂离子蓄电池(型号:063048)耐2C-10V的过充;在正常充放电状态下,环己苯的加入不影响电池的综合电性能。

Electrochemical properties and working mechanism of cyclohexyl benzene and triethyl amine as polymerizable electrolyte additives for overcharge protection of lithium ion batteries are studied by cyclic voltammetry, chargedischarge measurements and SEM. The experimental results reveal that cyclohexyl benzene electrochemically polymerize at 4.7 V （versus Li^＋/Li） to form a conductive polymer film on the cathode surface and the polymer may penetrate the separator to reach the anode surface, resulting an internal short-circuit to prevent the cell voltage runaway. The reaction between triethyl amine and H^＋ not only improves overcharging capability of Li-ion cells, but also holds back battery inflation. Cyclohexyl benzene and triethyl amine using jointly can let the Li-ion battery bear the overcharge of 2 C-10 V. Furthermore no severe detrimental effects of the application of cyclohexyl benzene were observed on the battery performances in normal state of charge-discharge.