Ultrafine Fe2VO4 nanoparticles anchored on Ti3C2Tx nanosheets (Fe2VO4@Ti3C2Tx) as high-energy anode for lithium-ion storage

Recently, as a new breakthrough for lithium-ion storage anode materials , transition metal vanadates , such as Fe 2 VO 4 , have attracted much attention, which, however, still suffer from slow electrochemical kinetics and substantial volume expansion. Hybrid with high conductivity materials is an effective route to deal with these issues. Herein, in situ synthesis of Fe 2 VO 4 @Ti 3 C 2 T x composites with porous sandwich structure by co-precipitation-calcination process was reported. Ultrafine Fe 2 VO 4 nanoparticles (10–15 nm) in situ grew and was anchored on Ti 3 C 2 T x nanosheets , which effectively inhibits both the grain growth for Fe 2 VO 4 and stacking for Ti 3 C 2 T x , thus facilitating the electrochemical kinetics and alleviating the volume change of Fe 2 VO 4 to maintain the integrated structure during the cycling process. As a result, Fe 2 VO 4 @Ti 3 C 2 T x anode shows high Li + diffusion coefficient (2.72 × 10 −11 cm 2 s −1 ) and pseudocapacitive charge storage mechanism (capacitive charge storage contribution 70.85–84.80 % at 0.2–1.0 mV s −1 ), which guarantee rapid charging and discharging capability. Consequently, outstanding rate performance (1012–595 mAh g −1 at 0.2–3.0 A g −1 ) and superior cycling capability (663 and 416 mAh g −1 at 1.0 A g −1 for 200 cycles and 2.0 A g −1 for 500 cycles, with the average capacity attrition rate of 0.059 % and 0.053 %, respectively), were achieved, which render Fe 2 VO 4 @Ti 3 C 2 T x composites important potential for lithium-ion storage.