Defect-independent migration of Li on C3B for Li-ion battery anode material

Two dimensional C₃B has attracted a lot of attentions due to its graphene-like structure. In this work, the potential of monolayer C₃B as anode material of lithium-ion battery are systematically studied through first-principles calculations. The results show that pristine C₃B has high stiffness (Young's modulus is 255.65 N/m), good binding strength of Li (−2.55~−2.66 eV), high capacity (1139.96 mA h/g) and good electronic (band gap is 0.64 eV) and ionic conductivity (diffusion barrier is 0.40 eV). It is also found that C₃B-V_C and C₃B-V_B has similar cohesive energy and formation energy. Interestingly, C₃B shows good defect-independent Li migration capability. The migration barrier of Li on defect C₃B was affected slightly by the vacancy, without the trap of Li. Moreover, the vacancy in C₃B could improve conductivity and the adsorption ability of Li without the sacrifice of migration ability of Li. These interesting properties indicate that C₃B has great potential for the application of anode material for LIBs.