【摘要】 报道石墨化介稳相碳微球 (MCMB)的嵌锂特性 ,着重研究其电化学嵌锂过程中动力学性能。国产MCMB材料具有良好的锂离子嵌入和脱出功能 ,首次放电容量达 330mAh/g ,充放电效率为 93.9%。XRD结构测量表明该材料与人造石墨的结构相近 ,用慢速扫描循环伏安法研究不同阶锂插入碳层化合物的组成 ,循环伏安法测定出锂离子扩散系数为3.8× 10 -12 cm2 /s。为研究介稳相碳微球电极嵌锂过程的动力学性质 ,还用交流阻抗法和电位阶跃法测定了在不同电极电位下锂离子的电化学扩散系数 ,表明随着锂嵌入量的增加 ,锂离子扩散系数逐渐减小。更多还原

【Abstract】 The electrode property of graphitized mesocarbon microbeads(MCMB)for Li ion battery had been studied extensively, particularly on the kinetic behavior of lithium ion intercalation process. The MCMB sample had a good reversible charge discharge performance with an initial discharge capacity of 330 mAh/g and charge discharge efficiency of 93.9%. The structure parameters of the MCMB sample obtained by XRD indicated that it was similar to artificial graphite. Lithium graphite intercalation compounds at different intercalation levels were investigated by slow scan rate cyclic voltammetry(SSCV). The value of Li ion electrochemical diffusion coefficient(D) was 3.8×10 -12 cm 2/s, which was measured by cyclic voltammetry(CV). For characterization of the kinetic behavior of the Li ion intercalation process, potentiostatic step chronoamperomtry(PSCA) and electrochemical impedance spectrum(EIS)were applied to measure the D values at various electrode potentials. The results show that D values decrease gradually with the increase of lithium intercalation into MCMB sample.更多还原