Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials
High‐energy Li‐rich layered cathode materials (≈900 Wh kg−1) suffer from severe capacity and voltage decay during cycling, which is associated with layered‐to‐spinel phase transition and oxygen redox reaction. Current efforts mainly focus on surface modification to suppress this unwanted structural...
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sg-ntu-dr.10356-1390202023-07-14T16:04:13Z Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials Zhang, Wei Sun, Yonggang Deng, Huiqiu Ma, Jianming Zeng, Yi Zhu, Zhiqiang Lv, Zhisheng Xia, Huarong Ge, Xiang Cao, Shengkai Xiao, Yao Xi, Shibo Du, Yonghua Cao, Anmin Chen, Xiaodong School of Materials Science and Engineering Innovative Centre for Flexible Devices Engineering::Materials Lithium Ion Battery Interface High‐energy Li‐rich layered cathode materials (≈900 Wh kg−1) suffer from severe capacity and voltage decay during cycling, which is associated with layered‐to‐spinel phase transition and oxygen redox reaction. Current efforts mainly focus on surface modification to suppress this unwanted structural transformation. However, the true challenge probably originates from the continuous oxygen release upon charging. Here, the usage of dielectric polarization in surface coating to suppress the oxygen evolution of Li‐rich material is reported, using Mg2TiO4 as a proof‐of‐concept material. The creation of a reverse electric field in surface layers effectively restrains the outward migration of bulk oxygen anions. Meanwhile, high oxygen‐affinity elements of Mg and Ti well stabilize the surface oxygen of Li‐rich material via enhancing the energy barrier for oxygen release reaction, verified by density functional theory simulation. Benefited from these, the modified Li‐rich electrode exhibits an impressive cyclability with a high capacity retention of ≈81% even after 700 cycles at 2 C (≈0.5 A g−1), far superior to ≈44% of the unmodified counterpart. In addition, Mg2TiO4 coating greatly mitigates the voltage decay of Li‐rich material with the degradation rate reduced by ≈65%. This work proposes new insights into manipulating surface chemistry of electrode materials to control oxygen activity for high‐energy‐density rechargeable batteries. NRF (Natl Research Foundation, S’pore) Accepted version 2020-05-14T14:40:53Z 2020-05-14T14:40:53Z 2020 Journal Article Zhang, W., Sun, Y., Deng, H., Ma, J., Zeng, Y., Zhu, Z., . . . Chen, X. (2020). Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials. Advanced Materials, 32(19), 2000496-. doi:10.1002/adma.202000496 0935-9648 https://hdl.handle.net/10356/139020 10.1002/adma.202000496 32239556 2-s2.0-85082748085 19 32 2000496 en Advanced Materials This is the peer reviewed version of the following article: Zhang, W., Sun, Y., Deng, H., Ma, J., Zeng, Y., Zhu, Z., . . . Chen, X. (2020). Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials. Advanced Materials, 32(19), 2000496-. doi:10.1002/adma.202000496, which has been published in final form at 10.1002/adma.202000496. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. application/pdf |
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Engineering::Materials Lithium Ion Battery Interface Zhang, Wei Sun, Yonggang Deng, Huiqiu Ma, Jianming Zeng, Yi Zhu, Zhiqiang Lv, Zhisheng Xia, Huarong Ge, Xiang Cao, Shengkai Xiao, Yao Xi, Shibo Du, Yonghua Cao, Anmin Chen, Xiaodong Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
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High‐energy Li‐rich layered cathode materials (≈900 Wh kg−1) suffer from severe capacity and voltage decay during cycling, which is associated with layered‐to‐spinel phase transition and oxygen redox reaction. Current efforts mainly focus on surface modification to suppress this unwanted structural transformation. However, the true challenge probably originates from the continuous oxygen release upon charging. Here, the usage of dielectric polarization in surface coating to suppress the oxygen evolution of Li‐rich material is reported, using Mg2TiO4 as a proof‐of‐concept material. The creation of a reverse electric field in surface layers effectively restrains the outward migration of bulk oxygen anions. Meanwhile, high oxygen‐affinity elements of Mg and Ti well stabilize the surface oxygen of Li‐rich material via enhancing the energy barrier for oxygen release reaction, verified by density functional theory simulation. Benefited from these, the modified Li‐rich electrode exhibits an impressive cyclability with a high capacity retention of ≈81% even after 700 cycles at 2 C (≈0.5 A g−1), far superior to ≈44% of the unmodified counterpart. In addition, Mg2TiO4 coating greatly mitigates the voltage decay of Li‐rich material with the degradation rate reduced by ≈65%. This work proposes new insights into manipulating surface chemistry of electrode materials to control oxygen activity for high‐energy‐density rechargeable batteries. |
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School of Materials Science and Engineering |
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School of Materials Science and Engineering Zhang, Wei Sun, Yonggang Deng, Huiqiu Ma, Jianming Zeng, Yi Zhu, Zhiqiang Lv, Zhisheng Xia, Huarong Ge, Xiang Cao, Shengkai Xiao, Yao Xi, Shibo Du, Yonghua Cao, Anmin Chen, Xiaodong |
format |
Article |
author |
Zhang, Wei Sun, Yonggang Deng, Huiqiu Ma, Jianming Zeng, Yi Zhu, Zhiqiang Lv, Zhisheng Xia, Huarong Ge, Xiang Cao, Shengkai Xiao, Yao Xi, Shibo Du, Yonghua Cao, Anmin Chen, Xiaodong |
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Zhang, Wei |
title |
Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
title_short |
Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
title_full |
Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
title_fullStr |
Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
title_full_unstemmed |
Dielectric polarization in inverse spinel‐structured Mg2TiO4 coating to suppress oxygen evolution of Li‐rich cathode materials |
title_sort |
dielectric polarization in inverse spinel‐structured mg2tio4 coating to suppress oxygen evolution of li‐rich cathode materials |
publishDate |
2020 |
url |
https://hdl.handle.net/10356/139020 |
_version_ |
1773551314147475456 |