Cathode healing methods for recycling of lithium-ion batteries

A review of physical processes used in the safe recycling of lithium ion batteries

“…Reuse or remanufacture: Recycling purely by physical means, such that the crystal structure or composition of the active material is not modified is termed "direct recycling" or "short loop recycling" in current literature [13,14,15,16,4,17,18,19,20,21]. Development of new battery chemistries may mean that LIBs with obsolete battery chemistries cannot be short loop recycled but must be chemically processed into a more relevant cell chemistry.…”

“…Extraction of the electrolyte through use of supercritical or subcritical CO 2 has been demonstrated by a variety of authors [14,13,24]. Such techniques offer the advantage of recovering the electrolyte solvent for purification and reuse rather than thermal recovery, and whilst some LiPF 6 recovery can be achieved with CO 2 alone, the addition of cosolvents has been shown to improve extraction [66].…”

Direct Recycling of Blended Cathode Materials by Froth Flotation

“…Many previous efforts have been devoted to regenerating aged cathode materials from spent LIBs. [23][24][25][26][27][28] There are two major challenges to be addressed to restore the electrochemical performance of aged cathode materials. First of all, the aged cathode may have lost lithium from its structure.…”

“…First of all, the aged cathode may have lost lithium from its structure. Hydrothermal treatment followed by an annealing process was developed to rejuvenate LiCoO 2 , [23] and LiNi 0.33 Co 0.33 Mn 0.33 O 2 (NMC111) in LiOH aqueous solutions, [24] and LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) in mixed LiOH/LiNO 3 molten salt solutions. [25] Second, the aged cathode undergoes phase and structural changes including cracking after numerous charge-discharge cycles that need to be repaired before reusing.…”

Advances of Carbon-Based Materials for Lithium Metal Anodes

“…Lithium metal anodes are known as the "Holy Grail" electrodes due to the unique advantages, such as the lowest density among metals, high theoretical specific capacity (3,860 mAh g −1 ) and the lowest electrochemical potential (−3.040 V vs. standard hydrogen electrode) (Xie et al, 2019;Shi et al, 2020;Zhou Y. et al, 2020). Moreover, when LMBs collocate with high capacity cathodes, such as sulfur (S) and oxygen (O 2 ), it can achieve excellent specific energy and be regarded as promising next-generation energy storage systems beyond LIBs and other storage systems (Hong et al, 2019;Sloop et al, 2019;Xiao et al, 2019;Gan et al, 2020;Guo et al, 2020;Li W. T. et al, 2020). Unfortunately, the development of LMBs is hindered by the inevitable shortcomings of lithium metal anode, including dendrite propagation, volume fluctuation, and unstable solid electrolyte interphase (SEI), originating from the high chemical reactivity and "hostless" nature of lithium metal during the plating/stripping process Pan et al, 2020).…”