Properties of Ti₂CO₂ and Ti₂CO₂/G heterostructures as anodes of sodium-ion batteries by first-principles study

In this study, the geometric and electronic properties of Ti2CO2 and Ti2CO2/G heterostructures as anode materials for sodium-ion batteries were systematically investigated using first-principles calculations. The storage mechanism and properties of sodium atoms on Ti₂CO₂ and Ti₂CO₂/G heterostructures were further studied. By comparing the adsorption energy (− 1.4 eV, − 1.26 eV), diffusion barrier (0.21 eV, 0.14 eV), storage capacity (478mAh/g, 528mAh/g), average open-circuit voltage (0.68 eV, 0.51 eV), and elastic modulus (161.40 N/m, 364.82 N/m) of sodium atoms on Ti₂CO₂ and Ti₂CO₂/G heterostructures, we found that Ti₂CO₂/G heterostructure exhibits superior structural stability, better electronic conductivity, higher storage capacity, lower average open-circuit voltage, lower diffusion barrier, and superior mechanical performance. Through this study, we explore the potential of Ti₂CO₂/G as an anode material for sodium-ion batteries and its sodium storage mechanism.