Multiscale structural NaTi2(PO4)3 anode for sodium-ion batteries with long cycle, high areal capacity, and wide operation temperature

Though plenty of research has been conducted to improve the low intrinsic electronic conductivity of NASICON-structured NaTi 2 (PO 4 ) 3 (NTP), realizing sodium-ion batteries with high areal/volumetric capacity still remains a formidable challenge. Herein, a multiscale design from anode material to electrode structure is proposed to obtain a gadolinium-ion-doped and carbon-coated NTP composite electrode (NTP-Gd-C), in which gadolinium ion doping, oxygen vacancy, optimized structure, N-doped carbon coating, and bridging on the three-dimensional network are simultaneously achieved. In the whole electrode, the excellent hierarchical electronic/ionic conductivity and structural stability are simultaneously improved via the synergistic optimization of NTP-Gd-C. As a result, excellent electrochemical performances of NTP-Gd-C electrode with a high areal/volumetric capacity of 1.0 mAh cm −2 /142.8 mAh cm −3 , high rate capability (58.3 mAh g −1 at 200 C), long cycle life (ultralow capacity fading of 0.004% per cycle under 10,000 cycles), and wide-temperature electrochemical performances (97.0 mAh g −1 at 2 C under −20°C) are achieved. Moreover, the NTP-Gd-C//Na 3 V 2 (PO 4 ) 3 /C full cell also delivers an excellent rate capacity of 42.0 mAh g −1 at 200 C and long-term high-capacity retention of 66.2% after 4000 cycles at 20 C. Highlights Developing high-performance sodium-ion batteries with the multiscale designed NaTi 2 (PO 4 ) 3 (NTP)-Gd-C material as the anode. Demonstrating the enhanced intrinsic ionic/electronic conductivity and structural stability of NTP-Gd-C electrode. Revealing the great potential for commercial applications of the NTP-Gd-C material.