Sc3+-doping effects on porous Li3V2(PO4)3/C cathode with superior rate performance and cyclic stability

An enhanced sol-gel combustion method was used to synthesize different porous Sc3+-doped Li3V2-xScx(PO4)(3)/C (x = 0.00, 0.05, 0.10 and 0.15) compounds. The substitution of Sc3+ into the V3+ sites of Li3V2-xScx(PO4)(3)/C expands the lattice volume along with the enlargement of Li+ diffusion channel, which is beneficial for Li+ transportation and ionic conductivity improvement. Besides, the Sc3+ doping content exhibits a great impact on the morphology of Li3V2-xScx(PO4)(3)/C composite. The pristine Li3V2(PO4)(3)/C are constituted of porous particles and nanorods, and the ratio of nanorods to particles can be controlled by adjusting the amount of Sc3+ doping since the ratio of nanorods to particles decreases with increasing Sc3+ doping content. When Sc3+ doping content increases to a certain level (x = 0.15, Li3V1.85Sc0.15(PO4)(3)/C), the nanorods are hardly seen. Li3V1.90Sc0.10(PO4)(3)/ C with higher tapped density, better reversibility, smaller resistance and larger Li+ diffusion coefficient demonstrates outstanding rate performance and cyclic stability, together with high specific discharge capacities of 130.2 and 92.9 mAh g(-1) at 0.5 and 20 C, respectively. Furthermore, a superior specific discharge capacity of 85.8 mAh g(-1) was retained at 20 C following 1000 cycles. Overall, a novel approach for the preparation of highperformance Li3V2-xScx(PO4)(3)/C cathodes with different morphologies for lithium-ion batteries is provided.

Automated summary

An enhanced sol-gel combustion method was used to synthesize porous Li3V2-xScx(PO4)(3)/C compounds with different Sc3+ doping contents, which improved Li+ transportation and ionic conductivity while influencing the morphology of the composites. The ratio of nanorods to particles in the composites decreased as the Sc3+ doping content increased. Li3V1.90Sc0.10(PO4)(3)/C exhibited outstanding rate performance and cyclic stability with high specific discharge capacities, showing potential for high-performance lithium-ion battery cathodes.