Constructing a boron-doped graphite anode with an accelerated Li+ diffusion dynamics for practical high-rate Li-ion batteries

Graphite anode materials have paved the way of commercial Li-ion batteries (LIBs) in energy storage systems (i.e., electric vehicles (EVs) and portable electronic devices). However, the further development of graphite anode still suffers from poor reversible capacity at high current densities and high-preparation cost from traditional high graphitization process (> 3000 °C), which limits applications of LIBs in high-power scenarios. Herein, we propose a novel but low-cost strategy to obtain the boron-doped graphite (BDG) material with accelerated dynamics of Li+ diffusion, produced by using boron carbide powder as graphitization catalyst at lower graphitization temperature of 2500 °C. The as-prepared BDG anode delivers a superior specific capacity of 368.4 mAh g−1 at 0.1 C and much better high-rate capacity with a six times reversible capacity at 5 C compared to that of commercial graphite. It is unveiled that the enhanced Li+ diffusion coefficient by ∼2 orders of magnitude (≈10−9 cm2 s–1) can be benefited from the rapid formation of Li2CO3/LiF-rich SEI layer at ∼1.1 V through boron doping. Such a low-cost strategy of BDG provides a promising anode material for the high-power application.