Systematic Study of Al Impurity for NCM622 Cathode Materials

Abstract

Many recycling processes have been developed for spent Li-ion batteries (LIBs), such as pyrometallurgy, hydrometallurgy, and direct recycling. For all the recycling methods, however, impurities are always introduced from the current collectors or casing materials, especially aluminum (Al), which might lead to negative effects on recovered electrode materials. Therefore, it is significant to determine the impacts of Al impurity on recovered materials. Here, the influence of the Al impurity for the synthesized LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) precursor and cathode is systematically studied. The cell with 0.2 at % Al impurity displays the highest reversible capacities (145.2, 130.5, and 100.3 mAh g −1 from 2, 3, and 5 C, respectively) and striking cycling capability at 2 C after 100 cycles with the highest retention capacity of 138.5 mAh g −1 . Meanwhile, the excess Al ions (5 at %) lead to the Li/Mn superlattice structure and deteriorate electrochemical performance of the synthesized NCM622 cathode.

Direct Recycling R&D at the ReCell Center

“…Therefore, experiments were performed to assess the effects of small quantities of copper and aluminum in recovered cathode product. Although metal fragments could cause shorts, small quantities of copper ions were actually found to improve cathode performance; similarly, aluminum ions improved capacity at very low levels but reduced it at higher levels [23,24]. Cell components such as packaging and separator pieces would be separated downstream, using other methods such as magnetic separation and air classification.…”

Nano-TiO2 coated single-crystal LiNi0.65Co0.15Mn0.2O2 for lithium-ion batteries with a stable structure and excellent cycling performance at a high cut-off voltage

“…[1][2][3][4][5] The discharge capacity of NCM is positively correlated with the nickel content, which means that nickel-rich materials (NCM622 (60% Ni) and NCM811 (80% Ni)) can better meet researchers' pursuit of high specic capacity. [6][7][8][9] Although these two materials have been or are being used in the automotive eld, various problems still hamper their practical application. The main issues include the lower safety and poor cycling performance of these materials, which originate from structural changes, mechanical degradation, and surface reactions.…”

A Roadmap for Transforming Research to Invent the Batteries of the Future Designed within the European Large Scale Research Initiative BATTERY 2030+

“…Although first results have been published, for example, the upscaling of LCO to LiNi 1/3 Mn 1/3 Co 1/3 O 2 , [ 146 ] this represents one of the major challenges to be tackled within the next few years. Several recycling processes are likely to cause impurities in directly recovered electrodes such as aluminum or copper fragments from the current collectors. [ 147 ] Even though such impurities can be beneficial in some cases, [ 148 ] generally, these direct recycling specific aspects need to be overcome to obtain reusable and competitive electrodes. Following the large quantities of EV batteries available on the market, new business cases are appearing, for example, the reuse of battery modules or cells after sorting to provide a longer service life or a second life. As a result, the batteries eventually coming to final recycling can be expected to be at a more advanced degradation stage and in a more mixed condition.…”