预嵌锂用穿孔集流体对锂离子电容器电化学性能的影响

发布时间：2018-03-20 11:24

本文选题：锂离子电容器　切入点：穿孔铜箔　出处：《物理化学学报》2017年04期 　论文类型：期刊论文

【摘要】：将石墨涂覆于传统铜箔(CCC)与穿孔铜箔(PCC)集流体表面,通过内部短路的方式进行预嵌锂处理,再以商业化的活性炭及预锂化的石墨分别为正、负极材料组装成锂离子电容器(LIC)。以PCC为集流体的LIC在0.1和2.0 A?g~(-1)的电流密度下,能量密度分别为118.2和51.7 Wh?kg~(-1),并且在0.5 A?g~(-1)的电流密度下循环1000次后的能量密度保持率为90%;以CCC为集流体的LIC在0.1和2.0 A?g~(-1)的电流密度下的能量密度分别为125.5和43.3 Wh?kg~(-1),在同等电流密度下2.0-3.8 V之间循环1000次后的能量密度保持率仅为73.2%。进一步研究表明,石墨采用PCC在预嵌锂的过程中避免了金属锂沉积,生成了均一且稳定的固体电解质膜(SEI),有效防止充放电过程中SEI膨胀,活性物质与集流体间粘结力降低,活性物质脱落等现象发生。因此,LIC通过PCC完成预嵌锂后的自放电及内阻更小,具有更佳的倍率性能和循环性能。
[Abstract]:The graphite was coated on the surface of the traditional copper foil CCC) and the perforated copper foil PCC. The pre-intercalated lithium was treated by internal short circuit. The commercial activated carbon and the pre-lithified graphite were respectively positive. The cathode materials were assembled to form lithium ion capacitors (LICs). The LIC with PCC as the collector was 0. 1 and 2. 0 A? The energy density is 118.2 and 51.7? KG-1, and at 0.5 A? At current density, the energy density retention rate of 1 000 cycles is 90. The LIC with CCC as fluid collector is 0. 1 and 2. 0 A? The energy density at current density is 125.5 and 43.3? The energy density retention rate after 1000 cycles between 2.0-3.8 V at the same current density is only 73.2%. Further study shows that the graphite can avoid lithium deposition in the process of pre-intercalation of lithium with PCC. A uniform and stable solid electrolyte membrane was formed, which effectively prevented the expansion of SEI during charge and discharge and the decrease of the adhesion between the active substance and the collector. Therefore, the self-discharge and internal resistance of the pre-intercalated lithium by PCC are smaller and have better rate performance and cycle performance.
【作者单位】：南京航空航天大学材料科学与技术学院江苏省能量转换材料与技术重点实验室;
【基金】：国家重点基础研究发展规划(973)(2014CB239701) 国家自然科学基金(51372116,51672128) 江苏省自然科学基金(BK20151468) 江苏省产学研前瞻性联合研究(BY-2015003-7) 江苏省高校优势学科建设工程(PAPD)资助项目~~
【分类号】：TM53

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