摘要
The development of layered sodium manganese oxide cathode materials with high capacity and structural stability is one of the keys to boosting the performance of sodium-ion batteries(SIBs),but it remains a great challenge.Herein,a titanium and fluorine codoped P2 type sodiummanganate of Na_(0.7)MnO_(2.05)cathode material(NMO-0.1TF)is developed as a high-capacity and long-durable cathode for highperformance SIBs.Titanium and fluorine codoping significantly reduces the structural deformation,synergistically improves structural stabilization,inhibits the formation of irreversible phases,and enhances electrochemical kinetics.As a result,the NMO-0.1TF||Na battery working in the voltage ranges of 2.0-4.2 V exhibits a high specific capacity of 227 mAh g^(−1)at a current density of 20 mA g^(−1)and an excellent rate performance(76 mAh g^(−1)at a high current density of 3 A g^(−1)).Such a battery still delivers an outstanding cycle stability,shows a high initial discharge capacity of 133 mAh g^(−1)at 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 codoped NMO-0.1TF cathode with high capacity and excellent stability represents a brilliantly practical application for developing high energy density SIBs.
基金
the National Natural Science Foundation of China(grant nos.22125903 and 51872283)
the Dalian Innovation Support Plan for High Level Talents(grant no.2019RT09)
the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2021002)
the Dalian National Laboratory for Clean Energy(DNL)
the CAS-DNL Cooperation Fund,CAS(grant nos.DNL201912,DNL201915,DNL202016,and DNL202019),and DICP(grant no.DICP I2020032).
