Serbessa Gashahun Gobena, Taklu Bereket Woldegbreal, Nikodimos Yosef, Temesgen Nigusu Tiruneh, Muche Zabish Bilew, Merso Semaw Kebede, Yeh Tsung-I, Liu Ya-Jun, Liao Wei-Sheng, Wang Chia-Hsin, Wu She-Huang, Su Wei-Nien, Yang Chun-Chen, Hwang Bing Joe
Nano-electrochemistry Laboratory, Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei City 106, Taiwan.
Battery Research Center of Green Energy, Ming-Chi University of Technology, New Taipei City 24301, Taiwan.
ACS Appl Mater Interfaces. 2024 Feb 28;16(8):10832-10844. doi: 10.1021/acsami.3c14763. Epub 2024 Feb 15.
Due to its good mechanical properties and high ionic conductivity, the sulfide-type solid electrolyte (SE) can potentially realize all-solid-state batteries (ASSBs). Nevertheless, challenges, including limited electrochemical stability, insufficient solid-solid contact with the electrode, and reactivity with lithium, must be addressed. These challenges contribute to dendrite growth and electrolyte reduction. Herein, a straightforward and solvent-free method was devised to generate a robust artificial interphase between lithium metal and a SE. It is achieved through the incorporation of a composite electrolyte composed of LiPSCl (LPSC), polyethylene glycol (PEG), and lithium bis(fluorosulfonyl)imide (LiFSI), resulting in the in situ creation of a LiF-rich interfacial layer. This interphase effectively mitigates electrolyte reduction and promotes lithium-ion diffusion. Interestingly, including PEG as an additive increases mechanical strength by enhancing adhesion between sulfide particles and improves the physical contact between the LPSC SE and the lithium anode by enhancing the ductility of the LPSC SE. Moreover, it acts as a protective barrier, preventing direct contact between the SE and the Li anode, thereby inhibiting electrolyte decomposition and reducing the electronic conductivity of the composite SE, thus mitigating the dendrite growth. The Li|Li symmetric cells demonstrated remarkable cycling stability, maintaining consistent performance for over 3000 h at a current density of 0.1 mA cm, and the critical current density of the composite solid electrolyte (CSE) reaches 4.75 mA cm. Moreover, the all-solid-state lithium metal battery (ASSLMB) cell with the CSEs exhibits remarkable cycling stability and rate performance. This study highlights the synergistic combination of the in-situ-generated artificial SE interphase layer and CSEs, enabling high-performance ASSLMBs.
由于其良好的机械性能和高离子导电性，硫化物型固体电解质（SE）有潜力实现全固态电池（ASSB）。然而，必须解决一些挑战，包括有限的电化学稳定性、与电极的固-固接触不足以及与锂的反应性。这些挑战导致枝晶生长和电解质还原。在此，设计了一种直接且无溶剂的方法，以在锂金属和SE之间生成坚固的人工界面。这是通过引入由LiPSCl（LPSC）、聚乙二醇（PEG）和双（氟磺酰）亚胺锂（LiFSI）组成的复合电解质来实现的，从而原位形成富含LiF的界面层。该界面有效地减轻了电解质还原并促进了锂离子扩散。有趣的是，加入PEG作为添加剂通过增强硫化物颗粒之间的粘附力提高了机械强度，并通过提高LPSC SE的延展性改善了LPSC SE与锂阳极之间的物理接触。此外，它起到保护屏障的作用，防止SE与锂阳极直接接触，从而抑制电解质分解并降低复合SE的电子导电性，进而减轻枝晶生长。Li|Li对称电池表现出显著的循环稳定性，在0.1 mA cm的电流密度下保持一致性能超过3000小时，复合固体电解质（CSE）的临界电流密度达到4.75 mA cm。此外，具有CSE的全固态锂金属电池（ASSLMB）单元表现出显著的循环稳定性和倍率性能。这项研究强调了原位生成的人工SE界面层和CSE的协同组合，实现了高性能的ASSLMB。
