Efficient separation and selective Li recycling of spent LiFePO₄ cathode

Abstract

Given the fast-growing demand for lithium-ion batteries (LIBs) and the upcoming climax of LIB retirement, efficient recycling of spent LIBs has shown increasing importance in both economic benefit and environmental conservation. The LIBs with LiFePO4 (LFP) cathodes account for half of the LIB market, so developing an appropriate recycling way for spent LFP (SLFP) batteries is imperative. In this work, a closed-loop regeneration of SLFP cathodes is proposed, in which a facile cold stimulation route is invented to peel the SLFP layer from Al foil, and then Li and Fe elements are selectively and efficiently extracted from the peeling SLFP layer under mild conditions based on an oxidant of NaClO. The leaching rate of elemental Li could reach 98.3%, and the regenerated LFP synthesized by recovered Li2CO3 and FePO4 shows exceptional performance with a discharge capacity of 162.6 mAh g-1 at 0.5 C. This regeneration route has greatly reduced the use of chemical reagents, shortened the process of impurity removal, and, therefore, realized the closed-loop regeneration of SLFP batteries.

Insertion of fluorine into a LiFePO4 electrode material by gas–solid fluorination

“…For that reason, LiFePO 4 (LFP) with the olivine crystal structure is one of the most widely used cathode materials for LIBs and is still studied nowadays. 7–9 Similarly, using fluorine led to higher potentials than oxygen due to the larger ionicity of M–F bonds as compared to M–O bonds. 10,11 With that, inorganic fluorides such as iron fluoride (FeF 3 ) and lithiated iron fluorides ( e.g.…”

Recycling valuable materials from the spent lithium ion batteries to catalysts: methods, applications, and characterization

“…Crucially, the midstream and downstream stages are intricately linked to the "catalysis". The primary methods employed in midstream recycling encompass pyrometallurgy [11][12][13] , hydrometallurgy [14][15][16][17] , and direct recycling [18][19][20][21][22][23] . Direct recycling emerges as a non-destructive method that directly collects and rejuvenates active electrode materials for LIBs.…”