摘要
Developing high-energy cathode for sodium ion batteries(SIBs)that enables 3-electron reaction is the most effective way to reduce high cost and solve range anxiety and safety hazards.Here,a novel NASICON-type Na_(4)MnCr(PO_(4))_(3)(NMCP)is synthesized as a high-energy cathode for SIBs.The as-prepared 6.4 wt%carbon-coated NMCP(NMCP@C)cathode annealed at 700°C delivers a discharge capacity of 107.3 mA h g^(−1)@0.1C,high rate capability up to 15C,and well capacity retention of 69.3%after 500 cycles at 5C within 1.4~4.3 V.Meanwhile,it also provides an exciting reversible capacity of 164.3 mA h g^(−1)@0.1C within 1.4~4.6 V and an ultrahigh energy density of 523.6 Wh kg^(−1).Moreover,high sodium ion diffusion coefficients(DNa+,10^(−12)~10^(−9) cm^(2) s−1)demonstrate the superior electrode process kinetics,and both solid solution and 2-phase reactions are involved in the sodium ion extraction/insertion process through ex situ x-ray diffraction analyses.Na_(3.3)La_(0.3)Zr_(1.7)Si_(2)PO_(12) with 3 wt%Na_(2)B_(4)O_(7) additive(NLZSP(NBO3))ceramic electrolyte is utilized to assemble NMCP@C//NLZSP(NBO3)//Na solid-state sodium metal batteries for the first time,which reveals an initial discharge capacity of 99.1 mA h g^(−1)(1.4~4.3 V)and 121.7 mA h g^(−1)(1.4~4.6 V)at 0.1C and an excellent cycling performance(capacity retention of 75.8%/72.6%after 100 cycles at 0.2C)at 30°C.All these confirm that NMCP@C is a high-energy cathode with great practical potential for all-solid-state SIBs.
基金
National Natural Science Foundation of China(62075100)
Natural Science Foundation of Nanjing University of Posts and Telecommunications(nos.NY220052 and NY221069).
