Improved Cycling Stability of Li[Ni0.90Co0.05Mn0.05]O2 Through Microstructure Modification by Boron Doping for Li‐Ion Batteries. Issue 25 (11th July 2018)

• Record Type: Journal Article
• Authors: Park, Kang‐Joon; Jung, Hun‐Gi; Kuo, Liang‐Yin; Kaghazchi, Payam; Yoon, Chong S.; Sun, Yang‐Kook
• Is Part Of: Advanced energy materials. Volume 8:Issue 25(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-07-11
• Subjects: boron -- Li‐ion batteries -- Ni‐rich NCM cathodes -- surface energy; 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.201801202
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Boron‐doped Li[Ni0.90 Co0.05 Mn0.05 ]O2 cathodes are synthesized by adding B2 O3 during the lithiation of the hydroxide precursor. Density functional theory confirms that boron doping at a level as low as 1 mol% alters the surface energies to produce a highly textured microstructure that can partially relieve the intrinsic internal strain generated during the deep charging of Li[Ni0.90 Co0.05 Mn0.05 ]O2 . The 1 mol% B‐Li[Ni0.90 Co0.05 Mn0.05 ]O2 cathode thus delivers a discharge capacity of 237 mAh g −1 at 4.3 V, with an outstanding capacity retention of 91% after 100 cycles at 55 °C, which is 15% higher than that of the undoped Li[Ni0.90 Co0.05 Mn0.05 ]O2 cathode. This proposed synthesis strategy demonstrates that an optimal microstructure exists for extending the cycle life of Ni‐rich Li[Ni1‐ x ‐ y Co x Mn y ]O2 cathodes that have an inadequate cycling stability in electric vehicle applications and indicates that an optimal microstructure can be achieved through surface energy modification. Abstract : Boron doping produces a highly textured microstructure of Li[Ni0.90 Co0.05 Mn0.05 ]O2 (NCM90) cathode, thus relieving the internal strain generated during charge and discharge cycling. Due to the unique morphology of the B‐doped NCM90, microcracking and electrolyte penetration are hindered, and formation of the NiO‐like impurity phase is confined. B‐doped NCM90 exhibits high capacity and excellent cycle life, especially at 55 °C.