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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, Co2VO4, 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 cm2 s−1, proving Co2VO4 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 m2 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.

Sodium-ion batteries (SIBs) are promising candidates for largescale energy storage systems due to the abundance and wide distribution of sodium resources. Various solutions have been successfully applied to revolve the large-ionsize-induced battery issues at the mid-to-low current density range. However, the fast-charging properties of SIBs are still in high demand to accommodate the increasing energy needs at large to grid scales. Herein, a core−shell Co 2 VO 4 / carbon composite anode is designed to tackle the fast-charging problem of SIBs. The synergetic effect from the stable spinel structure of Co 2 VO 4 , the size of the nanospheres, and the carbon shell provide enhanced Na + ion diffusion and electron transfer rates and outstanding electrochemical performance. With an ultrahigh current density of 5 A g −1 , the Co 2 VO 4 @C anode achieved a capacity of 135.1 mAh g −1 and a >98% capacity retention after 2000 cycles through a pseudocapacitive dominant process. This study provides insights for SIB fastcharging material design and other battery systems such as lithium-ion batteries.

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