Isolated Metalloid Tellurium Atomic Cluster on Nitrogen-Doped Carbon Nanosheet for High-Capacity Rechargeable Lithium-CO₂ Battery

Rechargeable Li-CO₂ battery represents a sustainable technology by virtue of CO₂ recyclability and energy storage capability. Unfortunately, the sluggish mass transport and electron transfer in bulky high-crystalline discharge product of Li₂CO₃, severely hinder its practical capacity and rechargeability. Herein, a heterostructure of isolated metalloid Te atomic cluster anchored on N-doped carbon nanosheets is designed (Te_AC@NCNS) as a metal-free cathode for Li-CO₂ battery. X-ray absorption spectroscopy analysis demonstrates that the abundant and dispersed Te active centers can be stabilized by C atoms in form of the covalent bond. The fabricated battery shows an unprecedented full-discharge capacity of 28.35 mAh cm⁻² at 0.05 mA cm⁻² and long-term cycle life of up to 1000 h even at a high cut-off capacity of 1 mAh cm⁻². A series of ex situ characterizations combined with theoretical calculations demonstrate that the abundant Te atomic clusters acting as active centers can drive the electron redistribution of carbonate via forming TeO bonds, giving rise to poor-crystalline Li₂CO₃ film during the discharge process. Moreover, the efficient electron transfer between the Te centers and intermediate species is energetically beneficial for nucleation and accelerates the decomposition of Li₂CO₃ on the Te_AC@NCNS during the discharge/charge process.