Mn-doped Co2(OH)3Cl xerogels with 3D interconnected mesoporous structures as lithium ion battery anodes with improved electrochemical performance

Abstract

Considering the merits of 3D mesoporous interconnected structures with a large surface area of xerogel and high theoretical capacity of Co₂(OH)₃Cl, which incorporates both chlorine and hydroxyl functional groups simultaneously, it is of great fundamental importance, as well as a challenge, to tune the porous structure, surface area, and functional doping to enhance the electrochemical performance of Co₂(OH)₃Cl xerogel anodes for lithium ion batteries (LIBs). Herein, for the first time, we report Mn-doped Co₂(OH)₃Cl 3D mesoporous xerogels assembled from nanoparticles via a one-step sol–gel method. The effect of Mn doping on the microstructures, surface area, charge transfer kinetics, and electrochemical performance of Mn-doped Co₂(OH)₃Cl xerogels was systematically investigated. It was observed that 4% Mn-doped Co₂(OH)₃Cl xerogels display excellent electrochemical performance, with a superior capacity of 1377 mA h g⁻¹ after 50 cycles at a current density of 100 mA g⁻¹. Even when the current density was increased to 1600 mA g⁻¹, it still retained a capacity of 824 mA h g⁻¹. The great enhancement in the electrochemical performance can be mainly due to the uniquely special 3D hierarchically porous interconnected xerogel structure with a high surface area, the enhancement of the electric conductivity and charge transfer kinetics, and the activated redox reaction kinetics related to LiOH and LiCl for the Mn-doped Co₂(OH)₃Cl xerogels.