B-doping tunes surface chemistry of graphite cathode interfaced at electrolyte for optimal anion storage and robust dual-ion batteries

Constructing a robust cathode-electrolyte interface (CEI) layer holds significant potential in enhancing the overall performance of dual-ion batteries (DIBs). However, the regulation of electrolyte components has been mainly focused on, while the negative impact of graphite edge structure is neglected. Herein, B-doped graphite (BDG) with a C-B coordination structure is used as the cathode material for DIB toward constructing a robust CEI layer. The surface C-B coordination is demonstrated to reduce the bond dissociation energy of electrolyte components (LiPF 6 and EMC), allowing for the fast formation of stable and high ionic conductivity CEI layer, which inhibits the continuous decomposition of the electrolyte and ensures the structural integrity of the cathode. Thus, the BDG electrode exhibits excellent rate performance and cycling stability (93.8 % after 1500 cycles at 10 C). Moreover, the as-assembled dual-carbon DIB (BDG as cathode, pre-lithiated graphite as anode) achieves a significant energy density of 178.5 Wh kg ‒1 at the high power density of 4 kW kg ‒1 . This work exerts a profound influence on the design of DIBs holding cost-efficiency, high power density and exceptional cycle life.