Yoon Seok Jung1
Yonsei University1
Solidification of electrolytes with inorganic superionic conductors is considered to significantly improve the safety of lithium-ion batteries. Moreover, inorganic solid electrolytes (SEs) have the potential of stabilizing high-capacity electrode materials. Currently, Li metal and Si anodes are considered promising to achieve the high energy of all-solid-state batteries. Although it has been revealed that most SEs also suffer from side reactions (reduction) in contact with Li metal anodes, various interfacial engineering has proved to be effective in improving the performance. Specifically, it was shown that an introduction of Ag-C interlayer in Li-free all-solid-state cells enabled reversible cycling of in situ formed Li metal anodes. However, the use of nanoparticles of Ag may act as a hurdle for the practical application. Besides, high-capacity Si anodes have also been investigated for all-solid-state batteries. The SE-free Si anodes demonstrated drastic outperformance over the conventional Si anodes including SEs. This result was indebted to the absence of parasitic side reactions caused by SEs in the anodes. However, the electrochemical performance was obtained under unrealistically high operating pressures.<br/>In this presentation, we report on our recent results of the strategies to develop high-capacity anodes of Si and Li metal for all-solid-state batteries. Specifically, it will be discussed how interlayer engineering for Si anodes enables stable operation at mild operational pressures, which is critical for practical all-solid-state batteries.