电解液对硫电极电化学性能的影响

Effect of electrolyte on electrochemical performance of sulfur electrode

采用恒流充放电、循环伏安等方法并结合电导率和粘度的测试,研究了电解液对硫电极电化学性能的影响。结果表明,在配制的电解液中,硫电极在2.3 V和2.0 V附近有两个放电电压平台,低电压平台的电位和电解液的粘度密切相关。当电解液为1 mol/L LiN(SO2CF3)2/1,3-二氧戊环(DOL)+乙二醇二甲醚(DME)(50∶50,体积比)时,在室温、0.4 mA/cm2的电流密度放电时,硫电极的首次放电比容量达1 050 mAh/g,第50次循环,放电比容量仍维持在600 mAh/g以上。

The influence of electrolyte on the electrochemical performance of sulfur electrode was investigated by galvanostatic charge-discharge and cycling voltammetry methods combined with conductivity and viscosity measurements. The results showed that sulfur electrodes based on the prepared electrolytes showed two voltage plateaus at around 2.3 V and 2.0 V, the voltage of lower voltage plateau was highly dependent on the viscosity of the electrolyte. When electrolyte was 1 mol/L LiN（SO2CF3）2/DOL ＋ D M E（50：50, vol）, the initial discharge specific capacity of sulfur electrode was 1 050 mAh/g at room temperature and discharge current density of 0.4 mA/cm^2. Its discharge specific capacity was above 600 mAh/g at the 50th cycle.