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DOI	10.1039/c9ta04841c
	The critical role of oxygen-evolution kinetics in the electrochemical stability of oxide superionic conductors
	Wang, Tiantian; Qiu, Wujie; Feng, Qi; Huang, Kui; Zhao, Xiaolin; Bao, Qisheng; Wang, Youwei; Zhu, Guannan; Liu, Jianjun
发表日期	2019
ISSN	2050-7488
EISSN	2050-7496
卷号	7 期号:28
英文摘要	Fast ion-conducting solid electrolytes could potentially overcome two key limitations of liquid electrolytes used in today's battery systems, namely, their flammability and limited electrochemical stability. In addition to high ionic conductivity, achieving a wide electrochemical window (EW) to suppress electronic transport (self-discharge and short circuiting) is particularly challenging. The superionic conductor Li7La3Zr2O12 (LLZO) exhibits a wide EW (>5.0 V) while maintaining a good ionic conductivity of similar to 10(-4) mS cm(-1), and serves as a model for promising superionic conductors. However, the physical origin of its electrochemical stability is not fully understood. Here, density functional theory (DFT) calculations demonstrated that a major contribution to the wide EW in LLZO originated from the high-barrier kinetics of electrochemical oxygen evolution. The high reaction barrier is attributed to electron holes occurring above the Fermi level, which is consistent with the high-voltage anionic redox potential. Based on the electron-hole relaxation capacity and polyhedral rigidity, we establish a combined charge and bond distance parameter q/r(3) which serves as the design principle for regulating electrochemical stability. Based on this principle, LLZO compounds with Nd3+, In3+, Sb3+, and Y3+ substituted in the Zr4+ site are predicted to have a wider electrochemical window of >5.5 V or even higher. The established anionic electrochemical mechanism for improving the electrochemical stability provides new insight into rationally designing and optimizing electrochemically stable superionic conductors.
学科领域	Chemistry; Energy & Fuels; Materials Science
语种	英语
WOS研究方向	Chemistry, Physical ; Energy & Fuels ; Materials Science, Multidisciplinary
来源期刊	JOURNAL OF MATERIALS CHEMISTRY A
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/112075
作者单位	Chinese Acad Sci, Shanghai Inst Ceram, State Key Lab High Performance Ceram & Superfine, 1295 Dingxi Rd, Shanghai 200050, Peoples R China
推荐引用方式 GB/T 7714	Wang, Tiantian,Qiu, Wujie,Feng, Qi,et al. The critical role of oxygen-evolution kinetics in the electrochemical stability of oxide superionic conductors[J]. 中国科学院西北生态环境资源研究院,2019,7(28).
APA	Wang, Tiantian.,Qiu, Wujie.,Feng, Qi.,Huang, Kui.,Zhao, Xiaolin.,...&Liu, Jianjun.(2019).The critical role of oxygen-evolution kinetics in the electrochemical stability of oxide superionic conductors.JOURNAL OF MATERIALS CHEMISTRY A,7(28).
MLA	Wang, Tiantian,et al."The critical role of oxygen-evolution kinetics in the electrochemical stability of oxide superionic conductors".JOURNAL OF MATERIALS CHEMISTRY A 7.28(2019).