Jeong Seongdeock, Park Sanghyuk, Beak Mincheol, Park Jangho, Sohn Jeong-Soo, Kwon Kyungjung
Department of Energy & Mineral Resources Engineering, Sejong University, Seoul 05006, Korea.
Mineral Resources Research Division, Resources Recovery Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Korea.
Materials (Basel). 2021 May 10;14(9):2464. doi: 10.3390/ma14092464.
As the explosive growth of the electric vehicle market leads to an increase in spent lithium-ion batteries (LIBs), the disposal of LIBs has also made headlines. In this study, we synthesized the cathode active materials Li[NiMnCo]O (NMC) and Li[NiMnCoFeAl]O (NMCFA) via hydroxide co-precipitation and calcination processes, which simulate the resynthesis of NMC in leachate containing trace amounts of iron and aluminum from spent LIBs. The effects of iron and aluminum on the physicochemical and electrochemical properties were investigated and compared with NMC. Trace amounts of iron and aluminum do not affect the morphology, the formation of O3-type layered structures, or the redox peak. On the other hand, the rate capability of NMCFA shows high discharge capacities at 7 C (110 mAh g) and 10 C (74 mAh g), comparable to the values for NMC at 5 C (111 mAh g) and 7 C (79 mAh g), respectively, due to the widened interslab thickness of NMCFA which facilitates the movement of lithium ions in a 2D channel. Therefore, iron and aluminum, which are usually considered as impurities in the recycling of LIBs, could be used as doping elements for enhancing the electrochemical performance of resynthesized cathode active materials.
随着电动汽车市场的爆发式增长导致废旧锂离子电池（LIBs）数量增加，LIBs的处理也成为了新闻头条。在本研究中，我们通过氢氧化物共沉淀和煅烧工艺合成了正极活性材料Li[NiMnCo]O（NMC）和Li[NiMnCoFeAl]O（NMCFA），这模拟了从废旧LIBs的含微量铁和铝的浸出液中重新合成NMC的过程。研究了铁和铝对物理化学和电化学性能的影响，并与NMC进行了比较。微量的铁和铝不会影响形态、O3型层状结构的形成或氧化还原峰。另一方面，NMCFA的倍率性能在7C（110 mAh g）和10C（74 mAh g）时显示出高放电容量，分别与NMC在5C（111 mAh g）和7C（79 mAh g）时的值相当，这是由于NMCFA的板间厚度增加，有利于锂离子在二维通道中的移动。因此，通常在LIBs回收中被视为杂质的铁和铝，可以用作掺杂元素来提高重新合成的正极活性材料的电化学性能。
