The role of the electrolyte in non-conjugated radical polymers for metal-free aqueous energy storage electrodes
The role of the electrolyte in non-conjugated radical polymers for metal-free aqueous energy storage electrodes
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DOI：
10.1038/s41563-023-01518-z
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发表时间：
2023-03-27
期刊：
影响因子：
41.2
通讯作者：
Lutkenhaus, Jodie L.
中科院分区：
文献类型：
--
作者：
Ma, Ting;Li, Cheng-Han;Lutkenhaus, Jodie L.
无金属水性电池有可能解决预计的战略金属短缺和锂离子电池中发现的安全问题。更具体地说，氧化还原活性非共轭自由基聚合物由于其高放电电压和快速氧化还原动力学而成为无金属水性电池的有希望的候选者。然而，人们对这些聚合物在水环境中的能量储存机制知之甚少。由于电子、离子和水分子的同时转移，反应本身很复杂且难以解析。在这里，我们通过使用电化学石英晶体微天平和一系列时间尺度的耗散监测来检查不同的混沌/亲液特性的水性电解质，展示了聚（2,2,6,6-四甲基哌啶氧基-4-基丙烯酰胺）的氧化还原反应的性质。令人惊讶的是，根据电解质的不同，容量可以变化高达 1,000%，其中某些离子可以实现更好的动力学、更高的容量和更高的循环稳定性。氧化还原活性非共轭自由基聚合物是无金属水性电池的有希望的候选者，但它们在水性环境中的储能机制仍不清楚。现在阐明了电解质在此类聚合物中用于设计无金属水性储能电极的作用。
Metal-free aqueous batteries can potentially address the projected shortages of strategic metals and safety issues found in lithium-ion batteries. More specifically, redox-active non-conjugated radical polymers are promising candidates for metal-free aqueous batteries because of the polymers' high discharge voltage and fast redox kinetics. However, little is known regarding the energy storage mechanism of these polymers in an aqueous environment. The reaction itself is complex and difficult to resolve because of the simultaneous transfer of electrons, ions and water molecules. Here we demonstrate the nature of the redox reaction for poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) by examining aqueous electrolytes of varying chao-/kosmotropic character using electrochemical quartz crystal microbalance with dissipation monitoring at a range of timescales. Surprisingly, the capacity can vary by as much as 1,000% depending on the electrolyte, in which certain ions enable better kinetics, higher capacity and higher cycling stability.Redox-active non-conjugated radical polymers are promising candidates for metal-free aqueous batteries but their energy storage mechanism in an aqueous environment remains unclear. The role of the electrolyte in such polymers for designing metal-free aqueous energy storage electrodes is now elucidated.