A safe and fast-charging lithium-ion battery anode using MXene supported Li₃VO₄

During fast charging, the commonly used Li-ion battery anode material, graphite, has a significant shortcoming, that is, its discharge potential is too low to guarantee the safety of batteries. Li₃VO₄ (LVO), an alternative anode material, has a safe discharge potential window of 0.5 V to 1.0 V vs. Li⁺/Li and high theoretical capacity (∼394 mA h g^-1). However, the poor conductivity of LVO (∼10^-10 S m^-1) constrains its further applications. In this paper, we innovatively embedded uniform LVO onto a multilayered material, Ti₃C₂T_x MXene, by a sol-gel method. The Ti₃C₂T_x MXene nanolayers with high electrical conductivity (2.4 × 10⁵ S m^-1) served as a scaffold to load LVO nanoparticles. The LVO/Ti₃C₂T_x MXene composite exhibited remarkable electrochemical performance in terms of rate capability and long-term cycle stability in comparison with bare LVO and commercial graphite anodes. The LVO/Ti₃C₂T_x MXene composite delivered an initial capacity of ∼187 mA h g^-1 and 146 mA h g^-1 after 1000 cycles at 5C, compared to bare LVO (an initial capacity of ∼41 mA h g^-1 and ∼40 mA h g^-1 after 1000 cycles at 5C) and graphite (∼71 mA h g^-1 after 1000 cycles at 5C). This work opens new possibilities of anode materials for safe and fast-charging Li-ion batteries.