Toward Efficient Recycling of Vanadium Phosphate-Based Sodium-Ion Batteries: A Review

Sodium-ion batteries (SIBs) have demonstrated noticeable development since the 2010s, being complementary to the lithium-ion technology in predominantly large-scale application niches. The projected SIB market growth will inevitably lead to the generation of tons of spent cells, posing a notorious issue for proper battery lifecycle management, which requires both the establishment of a regulatory framework and development of technologies for recovery of valuable elements from battery waste. While lithium-ion batteries are mainly based on layered oxides and lithium iron phosphate chemistries, the variety of sodium-ion batteries is much more diverse, extended by a number of other polyanionic families (crystal types), such as NASICON (Na3V2(PO4)(3)), Na3V2(PO4)(2)F-3 O-y(y), (0 <= y <= 2), KTiOPO4-type AVPO(4)X (A-alkali metal cation, X = O, F) and beta-NaVP2O7, with all of them relying on vanadium and phosphorous-critical elements in a myriad of industrial processes and technologies. Overall, the greater chemical complexity of these vanadium-containing phosphate materials highlights the need for designing specific recycling approaches based on distinctive features of vanadium and phosphorus solution chemistry, fine-tuned for the particular electrodes used. In this paper, an overview of recycling methods is presented with a focus on emerging chemistries for SIBs.

Automated summary

Sodium-ion batteries have shown significant development as a complementary technology to lithium-ion batteries in large-scale applications. However, the diversity of sodium-ion batteries poses challenges in recycling spent cells. Researchers need to design specific recycling methods to recover valuable elements.