ABSTRACT Among promising lithium salts for electrolyte in lithium‐ion batteries (LIBs), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) forms a more stable inorganic‐rich SEI layer. However, its implementation is limited by severe aluminum current collector corrosion. Since lithium hexafluorophosphate (LiPF 6 ) contributes a stable passivation layer for aluminum, a simply‐mixed LiPF 6 ‐LiTFSI dual‐salt electrolyte offers reduced corrosion. However, its corrosion inhibition capability is not complete. Herein, we propose a SEI‐stabilizing and corrosion‐preventing layer (SCL) that realizes spatial separation of salts, which confines concentrated LiTFSI within a polyethylene glycol dimethacrylate (PEGDMA) network at the anode‐LiPF 6 electrolyte interface. The locally high concentration of LiTFSI in SCL induces a kinetic preference that overrides the thermodynamic preference of LiPF 6 , which enables targeted decomposition of LiTFSI to form a robust SEI layer, while using only a small amount of LiTFSI. Furthermore, SCL demonstrates excellent corrosion‐inhibiting behavior compared to a simply‐mixed LiPF 6 ‐LiTFSI dual‐salt electrolyte. Consequently, SCL enables stable cycling of high‐loading (21.4 mg cm −2 ) practical NCM811/graphite full cells with 93.57% capacity retention after 100 cycles at a high current density of 2.2 mA cm −2 . This strategy enables selective electrochemical reactions through spatial confinement to enhance LIB performance, while suppressing side reactions and reducing costs, providing a scalable approach for next‐generation electrolyte design.
Kim et al. (Mon,) studied this question.