具有双原始立方体结构的区块共聚合物电解质:通过盐局部化增强固态导.
Hojun Lee1, Jihoon Kim1, Moon Jeong Park1
1Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
ACS nano
|January 3, 2025
概括
在块共聚合物中引入微量盐可以增强离子导电. 这种策略形成了稳定的立方体结构,显著提高了离子导电性,并减少了激活能量,以提高电池性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 聚合物科学 聚合物科学
背景情况:
- 块共聚合物电解质为固态电池提供了潜在的潜力.
- 在这些材料中实现高离子导电性仍然是一个挑战.
- 控制离子运输通路对于电解质性能至关重要.
研究的目的:
- 开发一种策略,以增强聚乙烯-块-聚乙烯氧化物 (PS-b-PEO) 电解质中的Li+导电.
- 调查Li+盐度和阳离子类型对电解质结构和导电性的作用.
- 探索稳定可取纳米结构形态的方法,以改善离子传输.
主要方法:
- 合成具有功能化末端组的PS-b-PEO块共聚合物.
- 在不同度下使用盐 (LiPF6,LiBF4,LiTFSI) 进行兴奋剂.
- 使用小角度X射线散射 (SAXS) 等技术进行结构性表征.
- 电化学阻抗光谱 (EIS) 用于测量离子导电性和激活能量.
主要成果:
- 添加微量Li+盐诱导了PS-b-PEO中双原始立方 (Im3̅m) 结构的形成.
- 与TFSI-.相比,较小的离子 (PF6-,BF4-) 在较宽的盐度范围内促进了Im3̅m结构的形成.
- 具有Im3̅m结构的电解质表现出明显更高的离子导电率和形态因子,而不是状形成的电解质.
- 观察到Li+导电的低激活能量 (0.012 eV),表明对聚合物放松的依赖性降低.
- 用酸盐部分功能化PEO终端组进一步增强了Im3̅m结构稳定性.
结论:
- 微量Li+盐的兴奋剂是一种有效的策略,可以增强PS-b-PEO电解质中的Li+导电.
- 形成Im3̅m结构是实现高离子导电性的关键.
- 离子选择和终端组功能化在稳定这些结构方面发挥着关键作用.
- 这种方法为开发用于离子电池的高性能固态电解质提供了有希望的途径.
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