Vapor phosphorus-coated cobalt vanadate as a high-performance anode for a lithium-ion battery

Vanadate-based synthesis of battery electrodes has become a topic of research interest due to the high lithium storage performance. However, the rapid capacity decay seriously hinders its practical application. In order to improve the potential for Co 3 V 2 O 8 (CVO) as an electrode in lithium batteries, a Na 5 V 12 O 32 nanowire precursor with a smooth surface was obtained using the hydrothermal method. Next, the CVO nanowires assembled by nanosheets were fabricated by cation exchange from the Na 5 V 12 O 32 precursor. Finally, the elemental phosphorus-coated CVO was successfully synthesized by a custom furnace. The characterization of X-ray diffraction (XRD) and inductively coupled plasma emission spectroscopy (ICP-ES) quantified the ratio of P and CVO, and Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) revealed the presence and coverage. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) further demonstrated the existence and morphology of P and CVO. Meanwhile, electrochemical measurements illustrated the stable lithium storage and notable rate performance of the P-CVO electrode as compared to AN-CVO. The P-CVO electrode holds a higher stable cycle performance after 190 cycles, with discharge specific capacity of 415.3 mA h g −1 and capacity retention of 97% at a current density of 1.0 A g −1 (872 mA h g −1 , 2.0 A g −1 , 98.8%), versus AN-CVO with 320.6 mA h g −1 (capacity retention of 79.5%) after only 100 cycles. Thence, the synthetic strategy provides a potential solution to enhance the stability of electrodes for high-performance lithium-ion batteries.