Constructing P-doped self-assembled V2C MXene/NiCo-layered double hydroxide hybrids toward advanced lithium storage

Abstract

To strengthen the stability of the anode structure of lithium-ion batteries (LIBs) and enhance the kinetics of their electrochemical reactions, we developed a new strategy to dope phosphorus into a hybrid of NiCo-layered double hydroxide (NiCo-LDH) nanosheets and three-dimensional (3D) multilayered V₂C MXene as the anode of high-performance LIBs. Owing to the 3D conductive network and large surface area of 3D V₂C multi-layer architectures, we set up a 3D conductive channel for rapid charge transfer and electrolyte storage, making the electrode and electrolyte fully in close contact. MXene, with its unique structure that can effectively resist volume expansion, can avoid the accumulation and breakage of NiCo-LDH nanosheets during the Li⁺ intercalation/deintercalation process. The synergistic effect between NiCo-LDH and MXene V₂C resulted in high structural stability and electrochemical activity of the material and phosphorus atomic doping, which provides richer redox reaction-activated sites with high electrical conductivity and low charge transfer impedance, leading to outstanding electrochemistry performance. The P-doped self-assembled V₂C MXene/NiCo-LDH (P-V2C/NiCo-LDH) maintains a specific capacity of 1077 mA h g⁻¹ after 700 cycles at a current density of 500 mA g⁻¹. The present strategy of the phosphorus doping route and coupling dual-metallic hydroxide with 3D V₂C can be used as novel electrodes for other types of high-performance energy storage devices.