Boron-deficient molecules tailored inorganic-rich cathode/electrolyte interfaces for stable Li||LiFe0.2Mn0.8PO4 battery

Tributyl borate (TBB) is among the widely used film-forming electrolyte additives in lithium-ion batteries (LIBs). It possesses the capability to produce an inorganic solid electrolyte interphase with abundant polar boron-containing compounds, functioning as a solid electrolyte interlayer (or cathode electrolyte interlayer), thus effectively isolating the electrode material from the electrolyte and averting parasitic reactions. Herein, the TBB could contribute to the formation of an inorganic solid electrolyte interphase rich in polar B-F and B-O bonds, thus enhancing the stability of the interface between the electrolyte and cathode materials. The findings demonstrate that the inclusion of 0.5 wt% TBB significantly enhances the stability of the electrode/electrolyte interface in Li‖LiMn_0.8Fe_0.2PO₄ batteries. After 600 cycles, the specific capacity reaches 107.9 mAh g⁻¹ with a capacity retention of 86.45%. This indicates outstanding electrochemical performance and excellent cycling stability. Consequently, TBB exhibits potential as an electrolyte additive for future high-energy density lithium batteries.