Abstract

Lithium-rich layered transition metal oxide positive electrodes offer access to anion redox at high potentials, thereby promising high energy densities for lithium-ion batteries. However, anion redox is also associated with several unfavorable electrochemical properties, such as open-circuit voltage hysteresis. Here we reveal that in Li1.17–xNi0.21Co0.08Mn0.54O2, these properties arise from a strong coupling between anion redox and cation migration. We combine various X-ray spectroscopic, microscopic, and structural probes to show that partially reversible transition metal migration decreases the potential of the bulk oxygen redox couple by > 1 V, leading to a reordering in the anionic and cationic redox potentials during cycling. First principles calculations show that this is due to the drastic change in the local oxygen coordination environments associated with the transition metal migration. We propose that this mechanism is involved in stabilizing the oxygen redox couple, which we observe spectroscopically to persist for 500 charge/discharge cycles.

Details

Title
Coupling between oxygen redox and cation migration explains unusual electrochemistry in lithium-rich layered oxides
Author
Gent, William E 1   VIAFID ORCID Logo  ; Lim, Kipil 2 ; Liang, Yufeng 3 ; Li, Qinghao 4 ; Barnes, Taylor 3 ; Sung-Jin, Ahn 5 ; Stone, Kevin H 6   VIAFID ORCID Logo  ; McIntire, Mitchell 7 ; Hong, Jihyun 2 ; Song, Jay Hyok 8 ; Li, Yiyang 9 ; Mehta, Apurva 6 ; Ermon, Stefano 7 ; Tyliszczak, Tolek 10 ; Kilcoyne, David 10   VIAFID ORCID Logo  ; Vine, David 10 ; Park, Jin-Hwan 5 ; Seok-Kwang Doo 5 ; Toney, Michael F 11   VIAFID ORCID Logo  ; Yang, Wanli 10   VIAFID ORCID Logo  ; Prendergast, David 3   VIAFID ORCID Logo  ; Chueh, William C 12 

 Department of Chemistry, Stanford University, Stanford, CA, USA; The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
 Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA 
 The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
 The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; School of Physics, National Key Laboratory of Crystal Materials, Shandong University, Jinan, China 
 Energy Lab, Samsung Advanced Institute of Technology, 130, Samsung-ro, Yeongtong-gu Suwon-si, Gyeonggi-do, South Korea 
 Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA 
 Department of Computer Science, Stanford University, Stanford, CA, USA 
 Energy1lab, Samsung SDI, 130, Samsung-ro, Yeongtong-gu Suwon-si, Gyeonggi-do, South Korea 
 Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA 
10  The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA 
11  Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA; Stanford Institute for Materials & Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA 
12  Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA; Stanford Institute for Materials & Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA 
Pages
1-12
Publication year
2017
Publication date
Dec 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1983427260
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.