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A P2‐Type Layered Superionic Conductor Ga‐Doped Na 2 Zn 2 TeO 6 for All‐Solid‐State Sodium‐Ion Batteries
Author(s) -
Li Yuyu,
Deng Zhi,
Peng Jian,
Chen Enyi,
Yu Yao,
Li Xiang,
Luo Jiahuan,
Huang Yangyang,
Zhu Jinlong,
Fang Chun,
Li Qing,
Han Jiantao,
Huang Yunhui
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201705466
Subject(s) - fast ion conductor , conductivity , analytical chemistry (journal) , ion , materials science , electrochemistry , diffusion , phase (matter) , doping , crystallography , inorganic chemistry , chemistry , electrolyte , thermodynamics , electrode , physics , optoelectronics , organic chemistry , chromatography
Here, a P2‐type layered Na 2 Zn 2 TeO 6 (NZTO) is reported with a high Na + ion conductivity ≈0.6×10 −3 S cm −1 at room temperature (RT), which is comparable to the currently best Na 1+ n Zr 2 Si n P 3− n O 12 NASICON structure. As small amounts of Ga 3+ substitutes for Zn 2+ , more Na + vacancies are introduced in the interlayer gaps, which greatly reduces strong Na + –Na + coulomb interactions. Ga‐substituted NZTO exhibits a superionic conductivity of ≈1.1×10 −3 S cm −1 at RT, and excellent phase and electrochemical stability. All solid‐state batteries have been successfully assembled with a capacity of ≈70 mAh g −1 over 10 cycles with a rate of 0.2 C at 80 °C. 23 Na nuclear magnetic resonance (NMR) studies on powder samples show intra‐grain (bulk) diffusion coefficients D NMR on the order of 12.35×10 −12 m 2 s −1 at 65 °C that corresponds to a conductivity σ NMR of 8.16×10 −3 S cm −1 , assuming the Nernst–Einstein equation, which thus suggests a new perspective of fast Na + ion conductor for advanced sodium ion batteries.