Phosphate‐functionalized Zirconium Metal–Organic Frameworks for Enhancing Lithium–Sulfur Battery Cycling
Phosphate‐functionalized Zirconium Metal–Organic Frameworks for Enhancing Lithium–Sulfur Battery Cycling
复制标题
磷酸盐-功能化锆金属-增强锂硫电池循环的有机框架
DOI：
10.1002/chem.202300821
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Thoi, V. Sara
中科院分区：
文献类型：
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作者：
Liu, Bingqian;Baumann, Avery E.;Butala, Megan M.;Thoi, V. Sara
锂硫电池由于其出色的理论能量密度而成为下一代储能设备的有希望的候选者。然而，它们具有低硫利用率和差的可循环性，极大地限制了它们的实际实施。在此，我们采用磷酸盐官能化的锆金属有机骨架（Zr-MOF）作为硫主体。凭借其多孔结构，卓越的电化学稳定性和合成多功能性，Zr-MOFs在防止可溶性多硫化物浸出方面具有巨大潜力。磷酸基团被引入到合成后的框架中，因为它们对多硫化锂表现出很强的亲和力，并且能够促进Li离子的传输。通过一系列技术，包括红外光谱、固态核磁共振光谱和X射线对分布函数分析，证明了磷酸盐在MOF-808中的成功掺入。当用于电池中时，与母体框架相比，磷酸盐官能化的Zr-MOF（MOF-808-PO 4）表现出显著增强的硫利用率和离子扩散，从而导致更高的容量和倍率性能。改进的容量保持率和抑制的自放电速率也证明了利用M0 F-808-P04的有效多硫化物包封。此外，我们通过检查在各种硫负载下的循环性能，探索了它们在高密度电池方面的潜力。我们使用混合无机-有机材料将结构与功能相关联的方法为推进电池材料提供了新的化学设计策略。
Lithium–sulfur batteries are promising candidates for next‐generation energy storage devices due to their outstanding theoretical energy density. However, they suffer from low sulfur utilization and poor cyclability, greatly limiting their practical implementation. Herein, we adopted a phosphate‐functionalized zirconium metal–organic framework (Zr‐MOF) as a sulfur host. With their porous structure, remarkable electrochemical stability, and synthetic versatility, Zr‐MOFs present great potential in preventing soluble polysulfides from leaching. Phosphate groups were introduced to the framework post‐synthetically since they have shown a strong affinity towards lithium polysulfides and an ability to facilitate Li ion transport. The successful incorporation of phosphate in MOF‐808 was demonstrated by a series of techniques including infrared spectroscopy, solid‐state nuclear magnetic resonance spectroscopy, and X‐ray pair distribution function analysis. When employed in batteries, phosphate‐functionalized Zr‐MOF (MOF‐808‐PO4) exhibits significantly enhanced sulfur utilization and ion diffusion compared to the parent framework, leading to higher capacity and rate capability. The improved capacity retention and inhibited self‐discharge rate also demonstrate effective polysulfide encapsulation utilizing MOF‐808‐PO4. Furthermore, we explored their potential towards high‐density batteries by examining the cycling performance at various sulfur loadings. Our approach to correlate structure with function using hybrid inorganic–organic materials offers new chemical design strategies for advancing battery materials.