Porous Co_(2)VO_(4) Nanodisk as a High-Energy and Fast-Charging Anode for Lithium-Ion Batteries

摘要

High-energy–density lithium-ion batteries(LIBs)that can be safely fast-charged are desirable for electric vehicles.However,sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density.Here we hypothesize that a cobalt vanadate oxide,Co_(2)VO_(4),can be attractive anode material for fast-charging LIBs due to its high capacity(~1000 mAh g^(−1))and safe lithiation potential(~0.65 V vs.Li^(+)/Li).The Li+diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15×10^(-10) cm^(2) s^(−1),proving Co_(2)VO_(4) a promising anode in fast-charging LIBs.A hexagonal porous Co2VO4 nanodisk(PCVO ND)structure is designed accordingly,featuring a high specific surface area of 74.57 m^(2) g^(−1) and numerous pores with a pore size of 14 nm.This unique structure succeeds in enhancing Li^(+) and electron transfer,leading to superior fast-charging performance than current commercial anodes.As a result,the PCVO ND shows a high initial reversible capacity of 911.0 mAh g^(−1) at 0.4 C,excellent fast-charging capacity(344.3 mAh g^(−1) at 10 C for 1000 cycles),outstanding long-term cycling stability(only 0.024% capacity loss per cycle at 10 C for 1000 cycles),confirming the commercial feasibility of PCVO ND in fast-charging LIBs.