基于石墨修饰型锂负极的锂-氧气电池  

Lithium anode based on graphite modified in Li-O_(2) battery

作　　者：谢坤池 解姝媛 施连旭[1,3] 刘佳 XIE Kun-chi;XIE Shu-yuan;SHI Lian-xu;LIU Jia(Aulin College,NortheastForestry University,Haerbin 150040,China;National&Local United Engineering Lab for Power Battery,Faculty of Chemistry,Northeast Normal University,Changchun 130024,China;College of Chemistry,Chemical Engineering and Resource Utilization,Northeast Forestry University,Haerbin 150040,China)

机构地区：[1]东北林业大学奥林学院,黑龙江哈尔滨150040 [2]东北师范大学化学学院,动力电池国家地方联合工程实验室,吉林长春130024 [3]东北林业大学化学化工与资源利用学院,黑龙江哈尔滨150040

出　　处：《分子科学学报》2022年第6期506-512,共7页Journal of Molecular Science

基　　金：中央高校基本科研业务费青年科研发展基金(2412020FZ007);吉林省教育厅重点项目(JJKH20221160KJ)。

摘　　要：采用简单易操作的物理涂层方法制备了基于石墨保护层的金属锂负极(Li@graphite复合电极),并研究了该复合电极在锂-氧气电池中的电化学性能.该保护层可以物理性隔绝锂金属与有机电解质的直接接触,降低副反应发生的可能性,其独特的结构和高电导性可成功诱导Li^(+)的均匀沉积,继而抑制锂枝晶生长.实验结果表明,保护层厚度为10μm时锂负极表面光滑均匀,含Li@graphite复合电极的锂-氧气电池可以循环176次(含纯Li负极的电池仅能循环5次),电池的稳定性得到提高.Li-O_(2)batteries with ultra-high theoretical energy density, environment-friendly and reversible cycles are considered to be the next-generation of storage system that may replace gasoline internal combustion engines. Lithium metal is a key component of Li-O_(2)battery. At present, there are three problems in lithium metal: the growth of lithium dendrite, the poor interface stability of lithium metal and the composition of SEI film is unstable. The above problems significantly reduce the Coulomb efficiency and cyclic stability of Li anode. Therefore, it is necessary to protect the Li anode to inhibit the growth of lithium dendrite and the occurrence of side reactions.One of the effective protective strategies is to construct a good protective layer for lithium ion conduction. The main function of this layer is to passivate the Li anode surface and avoid direct contact between Li anode and active substance. In this paper, We prepared a Li anode modified by a graphite-based protective layer(Li@graphite composite electrode) for Li-O_(2)battery and systematically investigated the electrochemical performance. The protective layer can physically isolation between Li metal and the organic electrolyte, which reduces the side reactions. Its unique structure and high conductivity can successfully induce uniform deposition of Li^(+), and then inhibit the growth of lithium dendrite. The surface of as-prepared anode is smooth and uniform. The thickness for the modified layer is about 10 μm. Compared with the pristine Li anode(which can be stably cycled for 5 times), the battery containing as-prepared anode exhibits a better cyclability of 176 times at a constant current density of 200 mA·g-1under a capacity limit of 500 mAh·g-1. At the same time, the oxygen positive electrode containing the Li@graphite battery was analyzed and tested. The experimental results showed that the discharge product Li2O_(2)can achieve reversible generation and decomposition, which indicates that the battery can maintain good reversibility in th

关 键 词：锂-氧气电池 锂负极 保护层 

分 类 号：O646[理学—物理化学]