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Title: High-performance heterostructured cathodes for lithium-ion batteries with a Ni-rich layered oxide core and a Li-rich layered oxide shell

The Ni-rich layered oxides with a Ni content of >0.5 are drawing much attention recently to increase the energy density of lithium-ion batteries. However, the Ni-rich layered oxides suffer from aggressive reaction of the cathode surface with the organic electrolyte at the higher operating voltages, resulting in consequent impedance rise and capacity fade. To overcome this difficulty, we present here a heterostructure composed of a Ni-rich LiNi 0.7Co 0.15Mn 0.15O 2 core and a Li-rich Li 1.2-xNi 0.2Mn 0.6O 2 shell, incorporating the advantageous features of the structural stability of the core and chemical stability of the shell. With a unique chemical treatment for the activation of the Li 2MnO 3 phase of the shell, a high capacity is realized with the Li-rich shell material. Aberration-corrected scanning transmission electron microscopy (STEM) provides direct evidence for the formation of surface Li-rich shell layer. Finally, the heterostructure exhibits a high capacity retention of 98% and a discharge- voltage retention of 97% during 100 cycles with a discharge capacity of 190 mA h g -1 (at 2.0–4.5 V under C/3 rate, 1C = 200 mA g -1).
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1]
  1. The Univ. of Texas, Austin, TX (United States)
  2. Ulsan National Institute of Science and Technology (UNIST), Ulsan (South Korea)
Publication Date:
Grant/Contract Number:
EE0006447
Type:
Accepted Manuscript
Journal Name:
Advanced Science
Additional Journal Information:
Journal Volume: 3; Journal Issue: 11; Journal ID: ISSN 2198-3844
Publisher:
Wiley
Research Org:
Univ. of Texas, Austin, TX (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; chemical activation; heterostructure; lithium-rich layered oxide; nickel-rich layered oxide; surface stabilization
OSTI Identifier:
1363894