Reuse of LiCoO₂ Electrodes Collected from Spent Li‐Ion Batteries after Electrochemical Re‐Lithiation of the Electrode

Abstract

The recycling of used Li-ion batteries is important as the consumption of batteries is increasing every year. However, the recycling of electrode materials is tedious and energy intensive with current methods, and part of the material is lost in the process. In this study, an alternative recycling method is presented to minimize the number of steps needed in the positive electrode recovery process. The electrochemical performance of aged and re-lithiated MgÀ Ti-doped LiCoO 2 and stoichiometric LiCoO 2 was investigated and compared. The results showed that after re-lithiation the structure of original LiCoO 2 was restored, the capacity of an aged LiCoO 2 reverted close to the capacity of a fresh LiCoO 2 , and the material could thus be recovered. The re-lithiated MgÀ Ti-doped LiCoO 2 provided rate capability properties only slightly declined from the rate capability of a fresh material and showed promising cyclability in half-cells. trated acids, which easily generates large amounts of waste solutions. Pyrometallurgy-based methods have a high efficiency and they are easy to scale up. [16,17] On the other hand, the high temperatures needed in the processes lead to high energy consumption and emissions. In addition, the recovery of lithium is difficult. [7,17] Biometallurgy-based methods utilize bacteria to extract metals from the spent lithium-ion batteries. [18,19] The methods are usually quite inexpensive, but as a downside the extraction processes are slow. [20] Lithium-ion batteries can be recycled either by processing the whole battery, [21][22][23][24] or dismantling the cells before starting the recovery process. [5,6,9,12,14,19,[25][26][27][28][29][30][31] The latter has been more popular in the literature, but the dismantling can be a laborious process without proper equipment. One could argue that this method is not easy to scale-up for industrial purposes. However, for example Nan et al. [12] reported about 5000 spent cells dismantled in 1 h, which indicates that scaling up should be possible. The advantage of recycling a whole lithium-ion battery is that the possibly challenging dismantling process is skipped, and thus one process step is reduced. However, having all the battery components in the same material flow initially can increase the amount of impurities in the final product. Additional process steps might be necessary to reduce the impurity concentrations in the recycled material. [24] Even if most of the elements are recovered with the above-mentioned methods, the typical layered structure of the metal oxide intercalation compounds is almost certainly lost, and the material downgraded. Typically, the positive electrode materials are reduced to more low-value chemicals, such as CoSO 4 , [4,12,23,24,31] Co-(OH) 2 , [5,9,32] CoCO 3 , [8,22] and Li 2 CO 3 , [4,9,12,24,31,32] during the recycling process. To synthesize these compounds back to Li-ion battery electrode materials requires energy. Therefore, if the structure of the original electrode material can be spared during the recycling process,...

Toward practical lithium-ion battery recycling: adding value, tackling circularity and recycling-oriented design

“…A range of cathodes, including LFP, LCO and NCM442 have reportedly been electrochemically regenerated with identical performance and characteristics as for the pristine materials. [184][185][186] However, a combination of Li metal source and organic liquid electrolyte, together with prohibitive cost and possible safety limits industrial application. To address aspects of process safety, electrochemical relithiation can be carried out in aqueous electrolyte followed by a heat treatment to sustainably recycle spent cathode materials.…”

Retrieving Spent Cathodes from Lithium‐Ion Batteries through Flourishing Technologies

“…The charge-discharge capacities of treated samples and commercially available samples were well examined within the voltage window of 2 to 4.5 V. They have found around 150 mAh g À 1 and 140 mAh g À 1, for the treated sample and commercial sample, respectively, with a better retention capacity of 93 % than that of the commercially LiCoO 2 (87 %). Lehtinen and co-workers [50] demonstrated the reuse of spent battery material by adding stoichiometric amounts of LiCoCo 2 (LCO) employing electrochemical techniques. The materials were aged in LCO/graphite pouch cells within the voltage range of 3.0-4.4 V at a current density 0.4 mA cm À 2 , and their properties were well documented.…”

Hydrogen-Treated Spent Lithium Cobalt Oxide as an Efficient Electrocatalyst for Oxygen Evolution

“…13 What's more, the original structure and components of the LIBs cathode material are ignored by them. 14 Therefore, it is of great significance to develop a new green recycling technology based on the original structure of spent lithium cobalt oxide (LiCoO 2 ). 15 Transition metal oxides have been considered potential oxygen evolution reaction (OER) catalysts because of their low prices and wide availability.…”

“…However, there are some shortcomings such as high cost, cumbersome steps, and easy to cause environmental pollution . What’s more, the original structure and components of the LIBs cathode material are ignored by them . Therefore, it is of great significance to develop a new green recycling technology based on the original structure of spent lithium cobalt oxide (LiCoO 2 ) …”