Nitrogen doping enhances pseudocapacitive lithium storage and ionic conductivity in Ti2Nb2O9 nanosheets

Titanium-niobium oxides (Ti x Nb y O 2x+2.5y ) are promising anode materials for lithium-ion batteries due to their suitable lithium insertion potential, excellent rate performance, cycling stability, and considerable capacity based on multi-electron reactions. However, the intrinsic low electrical conductivity and rapid capacity decay during cycling limit their application. In this study, nitrogen-doped Ti 2 Nb 2 O 9 nanosheets were synthesized using a chemical exfoliation method and the subsequent high-temperature phase transition. Meanwhile, introducing nitrogen atoms reduced the bandgap and increased the material's electrical conductivity. Thus, the lithium storage performance of the N-TNO electrode was improved with a reversible capacity of 348.1 mAh g −1 .