Oxygen-rich carbon cloth as a lithium deposition host for stable lithium metal anodes

Li metal is known as the most ideal anode material for Li-ion batteries due to its high theoretical capacity (3860 mA h g^-1) and low redox potential (-3.04 V vs. SHE). However, the dendrite growth and volume expansion caused by inhomogeneous and loose Li deposition limit the practical application of Li metal anode. Herein, oxidized carbon cloth (OCC) modified with oxygen-containing functional groups (-COOH, -C-OH, C[double bond, length as m-dash]O) is prepared by oxidation in a water bath environment. The polar oxygen-containing functional groups enhance the adsorption capacity of Li⁺, reduce the nucleation barrier, and effectively regulate the uniform distribution of Li⁺ on carbon fiber. Meanwhile, the large specific surface area of carbon fiber can reduce the local current density and inhibit dendrite formation. The sufficient internal space of the OCC can store the deposited Li, effectively easing the volume expansion. As such, the OCC‖Li half-cells exhibit a high coulombic efficiency (98.2%) after 250 cycles at 1 mA cm^-2. Besides, the OCC‖LiFePO₄ full cell capacity is 117 mA h g^-1 after 300 cycles at 1C. The experimental results show that the OCC prepared by a simple and efficient oxidation method plays a positive role in exploring high energy density Li metal batteries.