吉林大学杜菲团队报道了通过调节P2/P3非均质性和互易性来提高层状氧化物的K⁺离子电导率。相关研究成果于2024年9月03日发表在国际顶尖学术期刊《德国应用化学》。

固态钾金属电池因其低成本、高能量密度和固有安全性而成为电网规模储能的有前景的候选者。然而，由于K⁺离子的离子半径较大，固态K离子导体的离子导电性较差。

该文中，研究人员报告了P2/P3共生K_0.62Mg_0.54Sb_0.46O₂固体电解质（SE）的相异质性和互易性的精确调节，以在25°C下提高1.6×10^-4 S cm^-1的高离子电导率。通过阐明层状框架内原子堆叠模式对K⁺离子迁移势垒的影响，探索了体离子导电机制。

对于晶界处的离子扩散，P2/P3两相共生特性有助于调节SE微观结构，SE微观结构以长度为数十微米的棒状颗粒结晶，促进长距离离子传输并显著降低晶界电阻。

使用改性SE的钾金属对称电池在0.1mA cm^-2和0.68mA cm^-2的高临界电流密度下，具有超过300小时的出色循环寿命。准固态钾金属电池（QSSKBs）与两种层状氧化物阴极结合，在300次循环中表现出显著的稳定性，优于液体电解质电池。

QSSKB系统为高效、安全、耐用的大规模储能提供了一种有前景的策略。

附：英文原文

Title: Boosting K+-ionic Conductivity of Layered Oxides via Regulating P2/P3 Heterogeneity and Reciprocity for Room-temperature Quasi-solid-state Potassium Metal Batteries

Author: Xinyuan Zhang, Boqian Yi, Wanqing Jia, Shuoqing Zhao, Serguei Savilov, Shiyu Yao, Ze Xiang Shen, Gang Chen, Zhixuan Wei, Fei Du

Issue&Volume: 03 September 2024

Abstract: Solid-state potassium metal batteries are promising candidates for grid-scale energy storage due to their low cost, high energy density and inherent safety. However, solid state K-ion conductors struggle with poor ionic conductivity due to the large ionic radius of K+-ions. Herein, we report precise regulation of phase heterogeneity and reciprocity of the P2/P3-symbiosis K0.62Mg0.54Sb0.46O2 solid electrolyte (SE) for boosting a high ionic conductivity of 1.6×10-4 S cm-1 at 25 °C. The bulk ionic conducting mechanism is explored by elucidating the effect of atomic stacking mode within the layered framework on K+-ion migration barriers. For ion diffusion at grain boundaries, the P2/P3 biphasic symbiosis property assists in tunning the SE microstructure, which crystallizes in rod-like particles with lengths of tens of micrometers facilitating long-distance ion transport and significantly decreasing grain boundary resistance. Potassium metal symmetric cells using the modified SE deliver excellent cycling life over 300h at 0.1mAcm2 and a high critical current density of 0.68 mAcm2. The quasi-solid-state potassium metal batteries (QSSKBs) coupled with two kinds of layered oxide cathodes demonstrate remarkable stability over 300 cycles, outperforming the liquid electrolyte counterparts. The QSSKB system provides a promising strategy for high-efficiency, safe, and durable large-scale energy storage.

DOI: 10.1002/anie.202413214

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202413214