Environmental and economic assessment of structural repair technologies for spent lithium-ion battery cathode materials

The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work,a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO_(2) cathode materials.Compared with the spent cathode material with>50%Li deficiency,the Li/Co molar ratio of the regenerated LiCoO_(2) cathode is>0.9,which completely removes the Co_(3)O_(4) impurity phase formed by the decomposition of LixCoO_(2) in the failed cathode material after repair.The repaired LiCoO_(2) cathode mater-ials exhibit better cycling stability,lower electrochemical impedance,and faster Li^(+)diffusion than the commercial materials at both 1 and 10 C.Meanwhile,Li_(1.05)CoO_(2) cathodes have higher Li replenishment efficiency and cycling stability.The energy consumption and greenhouse gas emissions of LiCoO_(2) cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydro-metallurgical recycling processes.

Water-facilitated targeted repair of degraded cathodes for sustainable lithium-ion batteries

Directly repairing end-of-life lithium-ion battery cathodes poses significant chal-lenges due to the diverse compositions of the wastes.Here,we propose a water-facilitated targeted repair strategy applicable to various end-of-life batches and cathodes.The process involves initiating structural repair and reconstruct-ing particle morphology in degraded LiMn_(2)O_(4)(LMO)through an additional thermal drive post-ambient water remanganization,achieving elemental repair.Compared to solid-phase repair,the resulting LMO material exhibits superior electrochemical and kinetic characteristics.The theoretical analysis highlights the impact of Mn defects on the structural stability and electron transfer rate of degraded materials.The propensity of Mn ions to diffuse within the Mn layer,specifically occupying the Mn 16d site instead of the Li 8a site,theoretically sup-ports the feasibility of ambient water remanganization.Moreover,this method proves effective in the relithiation of degraded layered cathode materials,yielding single crystals.By combining low energy consumption,environmental friendli-ness,and recyclability,our study proposes a sustainable approach to utilizing spent batteries.This strategy holds the potential to enable the industrial direct repair of deteriorated cathode materials.

A green repair pathway for spent spinel cathode material:Coupled mechanochemistry and solid-phase reactions

A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.