Solid polymer electrolytes are typically designed to be amorphous and ion-rich, with fillers added to enhance ion conduction. However, lithium filament growth within these electrolytes poses a significant risk of battery failures. Here, we present findings on adaptive ion diffusion phenomena in highly crystalline, ion-free bulk poly(ethylene oxide) (PEO), involving ions such as Li+, Na+, K+, Mg2+, Zn2+, and Al3+. We developed a steady-state measurement method (SSMM) that overcomes the limitations of traditional electrochemical impedance spectroscopy, enabling the precise quantification of the adaptive diffusion coefficients in bulk PEO at various temperatures. Physicochemical and electrochemical characterizations reveal that continuous ion transport channels form through adaptive ion diffusion in bulk PEO while maintaining high crystallinity. Building on these characteristics, we proposed a solid-state electrolyte group (SSE-Group) using highly crystalline bulk PEO as an interlayer without adding fillers. This SSE-Group configuration suppresses the soft breakdown caused by lithium filament growth, improving cycle stability from 20 to 2500 h at 0.2 mA cm−2 in symmetrical lithium cells and enabling stable cycling for over 2000 cycles at 1C in solid-state batteries. Our findings enhance the understanding of adaptive ion diffusion and dendrite suppression in highly crystalline polymers, with the potential to improve the efficiency and safety of energy storage devices.

中文翻译：

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高结晶纯聚合物中的自适应离子扩散，用于稳定的固态电池


固体聚合物电解质通常设计为无定形且富含离子，并添加填料以增强离子传导。然而，这些电解质中的锂丝生长会带来电池故障的重大风险。在这里，我们介绍了高度结晶、无离子的本体聚（环氧乙烷）（PEO）中自适应离子扩散现象的研究结果，涉及 Li+、Na+、K+、Mg2+、Zn2+ 和 Al3+ 等离子。我们开发了一种稳态测量方法 （SSMM），它克服了传统电化学阻抗谱的局限性，能够精确量化各种温度下块状 PEO 中的自适应扩散系数。物理化学和电化学表征表明，连续离子传输通道是通过体 PEO 中的自适应离子扩散形成的，同时保持高结晶度。基于这些特性，我们提出了一种固态电解质基团 （SSE-Group），使用高结晶性块体 PEO 作为中间层，无需添加填料。这种 SSE 组配置抑制了锂丝生长引起的软击穿，提高了对称锂电池中 0.2 mA cm-2 下 20 至 2500 小时的循环稳定性，并在固态电池中实现了 1C 下超过 2000 次循环的稳定循环。我们的研究结果增强了对高结晶聚合物中自适应离子扩散和枝晶抑制的理解，有可能提高储能设备的效率和安全性。