Plasma assisted synthesis of LiNi0.6Co0.2Mn0.2O2 cathode materials with good cyclic stability at subzero temperatures

Layered Ni-rich cathode materials, LiNi0.6Co0.2Mn0.2O2 (NCM622), are synthesized via solid reaction assisted with a plasma milling pretreatment, which is resulted in lowering sintering temperatures for solid precursors. The plasma milling pretreated NCM622 cathode material sintered at 780. (named as PM-780) demonstrates good cycling stability at both room and subzero temperatures. Specifically, the PM-780 cathode delivers an initial discharge capacity of 171.2 mAh g(-1) and a high capacity retention of 99.7% after 300 cycles with current rate of 90 mA g(-1) at 30 degrees C, while stable capacities of 120.3 and 94.0 mAh g(-1) can be remained at similar to 10. and similar to 20. in propylene carbonate contained electrolyte, respectively. In-situ XRD together with XPS and SEM reveal that the NCM622 cycled at similar to 10. presented better structural stability and more intact interface than that of cathodes cycled at 30 degrees C. It is also found that subzero temperatures only limit the discharge potential of NCM622 without destroying its structure during cycling since it still exhibits high discharge capacity at 30. after cycled at subzero temperatures. This work may expand the knowledge about the low-temperature characteristics of layered cathode materials for Li-ion batteries and lay the foundation for its further applications. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Layered Ni-rich cathode materials, LiNi0.6Co0.2Mn0.2O2 (NCM622), synthesized through plasma milling method, show good cycling stability at both subzero and room temperatures. The cathodes cycled at subzero temperatures exhibit stable discharge capacities without structural damage, indicating the potential for low-temperature applications.