LIBs Solidelectrolyteinterphase(SEI)

LIBs Solid electrolyte interphase (SEI) SEI, a passive layer formed on the anode surface by the electrolyte reduction during the initial charging cycles plays an important role in the performance and degradation of LIBs [9]. The formation of SEI, its evolution, and degradation on the microscale are still not fully understood. SECM has been used substantially to explore the passivating properties of SEI on various electrodes such as graphite [6,10e13], Si-graphite [14], graphene [15e18], glassy carbon [19,20], copper [21,22], Li metal [23,24], silicon [25e27], silicon clathrate [28], and TiO2 [29e32]. As the SEI is delicate, spatially, and temporally dynamic in morphology and composition, it can easily get altered. Therefore, Zeng et al. used FB-SECM to investigate the electronically insulating SEI formed during the first lithiation and its partial decomposition in the subsequent delithiation on a graphite anode. Continued long-term cycling showed this SEI formation slowed and that the graphite surface was predominantly covered with insulating components [10]. Krueger et al. studied the protecting properties of SEI on a Li metal using SECM directly within the cell between chargeedischarge cycles (Figure 1) [23]. Using three applied battery cycling protocols, the development of protruding lithium deposits that are significantly electrochemically active was monitored (Figure 1d) [23]. The deposition of lithium can rupture SEI and expose fresh lithium that subsequently reacts with the electrolyte reforming the SEI [33]. 固体电解质界面（SEI） SEI 是在初始充电循环期间由电解质还原在阳极表面形成的钝化层，在 LIBs 的性能和降解方面起着重要作用[9]。SEI 的形成、演变和降解在微观尺度上的情况仍未完全明了。扫描电化学显微镜（SECM）已被广泛用于探究各种电极（如石墨、硅石墨、石墨烯、玻碳、铜、锂金属、硅、硅笼型化合物和二氧化钛）上 SEI 的钝化特性。由于 SEI 在形态和成分上具有空间和时间上的动态特性，且十分脆弱，因此很容易发生变化。因此，曾等人利用光纤扫描电化学显微镜（FB-SECM）研究了在石墨阳极上首次锂化过程中形成的电子绝缘 SEI 及其在随后脱锂过程中的部分分解情况。长期持续循环表明，SEI 的形成速度减缓，石墨表面主要被绝缘成分覆盖[10]。克鲁格等人利用扫描电化学显微镜（SECM）直接在电池内部对充电/放电循环期间锂金属上固体电解质界面（SEI）的保护特性进行了研究。 Current trends in SECM for energy storage devices: