Catalytic Strategies Enabled Rapid Formation of Homogeneous and Mechanically Robust Inorganic‐Rich Cathode Electrolyte Interface for High‐Rate and High‐Stability Lithium‐Ion Batteries

Abstract

Abstract Lithium iron phosphate (LFP) cathode is renowned for high thermal stability and safety, making them a popular choice for lithium‐ion batteries. Nevertheless, on one hand, the fast charge/discharge capability is fundamentally constrained by low electrical conductivity and anisotropic nature of sluggish lithium ion (Li + ) diffusion. On the other hand, the interface and internal structural degradation occurs when subjected to high‐rate condition. Herein, a multifunctional boron‐doping graphene/lithium carbonate (BG/LCO) nanointerfacial layer on surface of commercial LiFePO 4 particles is designed, in which the BG layer catalyzes the rapid reaction of Li 2 CO 3 ‐LiPF 6 for homogeneous and mechanically robust inorganic LiF‐rich structure across the cathode‐electrolyte interphase (CEI), forms a conductive network to significantly enhance both electron and Li + transport, and strengthens the FeO bonding to minimize both Fe loss and the formation of Fe‐Li antisite defects. Correspondingly, the modified LFP cathode achieves a high capability of 113.2 mAh g −1 at 10 C and extraordinary cyclic stability with 88.0% capacity retention over 1000 cycles as compared to the pristine LFP cathode with a capacity of only 94.0 mAh g −1 and 64.6% capacity retention. It also exhibits great enhancements of 20.1% and 3.7% at higher‐rate condition (room temperature/15 C) and the low temperature condition (−10 °C/1 C), respectively.