戴雨晴博士论文”Improving the Interfacial Stability of Ultrahigh-Nickel Cathode with PEO-based Electrolyte by Targeted Chemical Reactions“被Chemical Science接收发表
发布时间：2024-07-13
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Benefiting from high energy density of the ultrahigh-nickel cathode materials and good safety of the PEO-based electrolytes, PEO-based ultrahigh-nickel solid-state lithium batteries (SLMBs) are considered to be new-generation energy storage devices. However, the incompatibility of ultrahigh-nickel cathode materials and PEO-based electrolytes is the main challenge due to serious interfacial side reactions. Therefore, the modification of cathode/electrolyte interface is crucial. Herein, the residual lithium on the surface of LiNi0.9Co0.06Mn0.04O2 is utilized to construct an interfacial coating layer by reacting with H3BO3. The in-situ formed xLi2O-B2O3 coating layer (LBO1-NCM) with high ionic conductivity can be regulated with different crystal structures during the sintering process. Besides, an all-solid-state three-electrode cell is fabricated, which verifies that the xLi2O-B2O3 coating can effectively stabilize the interface. Astonishingly, the uneven Li anode deposition is observed in SLMBs, which is caused by the breakage of PEO molecular chains due to the strong oxidation of cathode, while this crosstalk is also suppressed by xLi2O-B2O3 coating layer. Consequently, the Li|PEO|LBO1-NCM achieves a substantially improved electrochemical performance, exhibiting 90.5% of capacity retention after 100 cycles for the coin cell and 80.3% of capacity retention after 200 cycles for the pouch cell. As a vision, the targeted modification of interfaces should be paid as much attention as electrolyte optimization in SLMBs.