In-situ continuous hydrothermal synthesis of TiO₂ nanoparticles on conductive N-doped MXene nanosheets for binder-free Li-ion battery anodes

Anode materials are key to determining the energy density, cyclability and of life recyclability for Li-ion energy storage systems. High surface area materials, such as MXenes, can be manufactured with improved electrochemical properties that remove the need for polymeric binders or hazardous chemicals that pose a challenge to recycle Li-ion batteries. However, there remains a challenge to produce Li-ion anode materials that are binder free and poses energy storage characteristics that match the current carbon-based electrodes. Here we show the synthesis of N-doped MXene-TiO₂ hybrid anode materials using an aqueous route. N-doped TiO₂-MXene was modified using a single step continuous hydrothermal process. Capacity tests indicate an improvement from the initial specific energy capacity of 305 mAhg⁻¹ to 369 mAhg⁻¹ after 100 cycles at a charge rate of 0.1 C and a Coulombic efficiency of 99.7%. This compares to 252 mAhg⁻¹ for the unmodified MXene which exhibited significant capacity fade to 140 mAhg⁻¹. The ability to manufacture a Li-ion anode that does not require toxic chemicals for processing into an electrode and exhibits good energy storage characteristics in a binder free system is a significant step forward for energy storage applications.