P.C. Wen, H.D. Shi, D.D. Guo, A. Wang, Y. Yu*, Z.-S. Wu*

Renewables, 2023, 1.

DOI: 10.31635/renewables.022.202200012 [PDF]

The development of layered sodium manganese oxidescathode materials with high capacity and structural stability is one of the keys to boost the performance of sodium-ion batteries (SIBs), but remains a great challenge. Herein, a titanium and fluorine co-dopedP2 type sodium manganate ofNa_0.7MnO_2.05cathode material (NMO-0.1TF) is developed as high-capacity and long-durable cathode for high-performance SIBs. The titanium and fluorine co-doping could significantly reduce the structural deformation, synergistically improved structural stabilization, inhibit the formation of irreversible phases and enhance electrochemical kinetics. As a result, the NMO-0.1TF||Na battery workingin the voltage ranges of 2.0-4.2 V exhibits a high specific capacity of 227 mAh g^-1at current density of 20 mA g^-1, and excellent rate performance (76 mAh g^-1at a high current density of 3 A g^-1). Such battery still delivers an outstanding cycle stability, shows a high initial discharge capacity of 133 mAh g^-1at 1 A g^-1, and maintains the initial capacity of 96.2% after 200 cycles. More importantly, the assembled full battery of NMO-0.1TF||hard carbon validates high capacity and impressive cyclability. Therefore, this co-doped NMO-0.1TF cathode with high capacity and excellent stability presents brilliantly practical application for developing high energy density SIBs.