Development of tin oxide-embedded phosphovanadate glass-ceramics as cathode and anode materials for high-performance secondary batteries

Vanadate glass, having semiconductor-level electrical conductivity, is a promising candidate as a new electrode material for secondary batteries. This study investigated the relationship between the structure and electrode active performance of tin phosphovanadate glass-ceramics having the following composition: xP 2 O 5 -(90- x ) V 2 O 5 -10SnO 2 ( x PVS) with x ranging from 10 to 60 mol%. The series of glass samples were prepared by melt-quenching and characterised by differential thermal analysis (DTA), X-ray diffractometry (XRD), 119 Sn Mössbauer spectroscopy (SnMS), electrochemical impedance spectroscopy (EIS), X-ray absorption fine structure (XAFS) and charge-discharge capacity test in lithium-ion batteries (LIB) and sodium-ion batteries (SIB). According to the secondary battery performance test, the largest initial discharge capacities of 350 mAh g -1 in LIB and 64.3 mAh g -1 in SIB under the current density of 50 mA g -1 were recorded using 10PVS cathode. As for the capacity retention in LIB, 10PVS was the highest at 71.4%, while that for SIB was 67.3%. In terms of the large capacity and capacity retention, it is concluded that 10PVS is the best cathode for secondary batteries among the samples investigated in this study. For the anode performance of xPVS glasses, the 10PVS demonstrates the high initial discharge capacity (370 mAh g -1 ) in LIB, and 90 mAh g -1 in SIB under the same current density. After 30 cycles, the capacity retention is 60% for LIB and 54% for SIB. Thus, xPVS glasses show potential as both cathode and anode materials in LIB and SIB, with 10PVS exhibiting the best overall performance.