Structural and electrochemical properties of Fe- and Al-doped Li3V2(PO4)3 for all-solid-state symmetric lithium ion batteries prepared by spray-drying-assisted carbothermal method
Abstract Li 3 V 2 (PO 4 ) 3 and Li 3 V 1.9 M 0.1 (PO 4 ) 3 (M = Fe, Al) samples were synthesized via spray-drying-assisted carbothermal solid-state reaction, and their structural and electrochemical properties were investigated by XRD, SEM, and galvanostatic charge/discharge. Li 3 V 2 (PO 4 ) 3 , Li 3 V 1.9 Fe 0.1 (PO 4 ) 3 , and Li 3 V 1.9 Al 0.1 (PO 4 ) 3 showed initial discharge capacities of 103.3 mAh g − 1 , 107.6 mAh g − 1 , and 105.6 mAh g − 1 , respectively, in the all-solid-state symmetric batteries with Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 solid-state electrolytes at a rate of 7.5 mA g − 1 . The enhanced discharge capacities of Fe and Al-doped Li 3 V 2 (PO 4 ) 3 could be attributed to the increased electrical conductivity induced by the introduction of Fe 3 + or Al 3 + trivalent ions into the V 3 + sites and to the structural stabilization of the monoclinic Li 3 V 2 (PO 4 ) 3 by the spray-drying process.