Cobalt‐Free High‐Capacity Ni‐Rich Layered Li[Ni0.9Mn0.1]O2 Cathode. Issue 4 (10th December 2019)

• Record Type: Journal Article
• Authors: Aishova, Assylzat; Park, Geon‐Tae; Yoon, Chong S.; Sun, Yang‐Kook
• Is Part Of: Advanced energy materials. Volume 10:Issue 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-12-10
• Subjects: cobalt free -- long‐term cycling -- microcrack suppression -- role of manganese -- strain relaxation; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201903179
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Li[Ni0.9 Co0.1 ]O2 (NC90), Li[Ni0.9 Co0.05 Mn0.05 ]O2 (NCM90), and Li[Ni0.9 Mn0.1 ]O2 (NM90) cathodes are synthesized for the development of a Co‐free high‐energy‐density cathode. NM90 maintains better cycling stability than the two Co‐containing cathodes, particularly under harsh cycling conditions (a discharge capacity of 236 mAh g −1 with a capacity retention of 88% when cycled at 4.4 V under 30 °C and 93% retention when cycled at 4.3 V under 60 °C after 100 cycles). The reason for the enhanced stability is mainly the ability of NM90 to absorb the strain associated with the abrupt anisotropic lattice contraction/extraction and to suppress the formation of microcracks, in addition to enhanced chemical stability from the increased presence of stable Mn 4+ . Although the absence of Co deteriorates the rate capability, this can be overcome as the rate capability of the NM90 approaches that of the NCM90 when cycled at 60 °C. The long‐term cycling stability of NM90 is confirmed in a full cell, demonstrating that it is one of the most promising Co‐free cathodes for high‐energy‐density applications. This study not only provides insight into redefining the role of Mn in a Ni‐rich cathode, it also represents a clear breakthrough in achieving a commercially viable Co‐free Ni‐rich layered cathode. Abstract : A Co‐free Ni‐rich Li[Ni0.9 Mn0.1 ]O2 layered oxide cathode is proposed as a high energy density, low‐cost, and environmentally benign cathode material for lithium‐ion batteries: by removing the most expensive and hazardous element; cobalt. Outstanding microstructural stability of the material results in excellent cycling performance, which outperforms Co‐containing cathodes Li[Ni0.9 Co0.1 ]O2 and Li[Ni0.9 Co0.05 Mn0.05 ]O2 .