Synthesis and electrochemical properties of porous LiV3O8 as cathode materials for lithium-ion batteries

Highlights: → Porous LiV3O8 are synthesized by a tartaric acid-assisted sol-gel process. → The presence of tartaric acid enables growth of porous LiV3O8 with high surface area. → Porous LiV3O8 exhibit higher discharge capacity and improved long-term cyclabiligy. → Improved electrochemical performance is contributed to enhanced charge transfer kinetics. - Abstract: In this paper, we report on the synthesis of porous LiV3O8 by using a tartaric acid-assisted sol-gel process and their enhanced electrochemical properties for reversible lithium storage. The crystal structure, morphology and pore texture of the as-synthesized samples are characterized by means of XRD, SEM, TEM/HRTEM and N2 adsorption/desorption measurements. The results show that the tartaric acid plays a pore-making function and the calcination temperature is an important influential factor to the pore texture. In particular, the porous LiV3O8 calcined at 300 deg. C (LiV3O8-300) exhibits hierarchical porous structure with high surface area of 152.4 m2 g-1. The electrochemical performance of the as-prepared porous LiV3O8 as cathode materials for lithium ion batteries is investigated by galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The porous LiV3O8-300 displays a maximum discharge capacity of 320 mAh g-1 and remains 96.3% of its initial discharge capacity after 50 charge/discharge cycles at the current density of 40 mA g-1 due to the enhanced charge transfer kinetics with a low apparent activity energy of 35.2 kJ mol-1, suggesting its promising application as the cathode material of Li-ion batteries.