Wide Potential Window Supercapacitors Using Open‐Shell Donor–Acceptor Conjugated Polymers with Stable N‐Doped States
Wide Potential Window Supercapacitors Using Open‐Shell Donor–Acceptor Conjugated Polymers with Stable N‐Doped States
复制标题
DOI：
10.1002/aenm.201902806
复制
发表时间：
2019-10
影响因子：
27.8
通讯作者：
Kaiping Wang;Lifeng Huang;N. Eedugurala;Song Zhang;Md Abdus Sabuj;N. Rai;X. Gu;J. Azoulay;
中科院分区：
文献类型：
--
作者：
Kaiping Wang;Lifeng Huang;N. Eedugurala;Song Zhang;Md Abdus Sabuj;N. Rai;X. Gu;J. Azoulay;
超级电容器已成为一种重要的储能技术，具有快速功率传输、快速充电和长循环寿命等优点。虽然提高工作电压可改善整体能量和功率密度，但由于缺乏稳定的n型氧化还原活性材料，进展仍然受阻。在此，展示了一种由窄带隙给体 - 受体共轭聚合物组成的新型法拉第电极材料，它在基态具有开壳层结构、本征导电性，并且在还原态下电荷离域增强。这些特性使阳极具有非常高的稳定性，库仑效率达到99.6%，在2000次充放电循环后仍能保持90%的电容，超过了其他可n掺杂的有机材料。通过光电测量对氧化还原循环过程进行原位监测，以区分化学和物理降解机制。使用这种聚合物与p型PEDOT:PSS制成的非对称超级电容器在3V的电位窗口内工作，在1A g⁻¹放电速率下能量密度达到30.4 Wh kg⁻¹，处于同类最佳水平，在10A g⁻¹放电速率下功率密度为14.4 kW kg⁻¹，并且具有对储能和管理至关重要的长循环寿命。这项工作展示了一类新型稳定且可调节的氧化还原活性材料在可持续能源技术中的应用。
Supercapacitors have emerged as an important energy storage technology offering rapid power delivery, fast charging, and long cycle lifetimes. While extending the operational voltage is improving the overall energy and power densities, progress remains hindered by a lack of stable n‐type redox‐active materials. Here, a new Faradaic electrode material comprised of a narrow bandgap donor−acceptor conjugated polymer is demonstrated, which exhibits an open‐shell ground state, intrinsic electrical conductivity, and enhanced charge delocalization in the reduced state. These attributes afford very stable anodes with a coulombic efficiency of 99.6% and that retain 90% capacitance after 2000 charge–discharge cycles, exceeding other n‐dopable organic materials. Redox cycling processes are monitored in situ by optoelectronic measurements to separate chemical versus physical degradation mechanisms. Asymmetric supercapacitors fabricated using this polymer with p‐type PEDOT:PSS operate within a 3 V potential window, with a best‐in‐class energy density of 30.4 Wh kg−1 at a 1 A g−1 discharge rate, a power density of 14.4 kW kg−1 at a 10 A g−1 discharge rate, and a long cycle life critical to energy storage and management. This work demonstrates the application of a new class of stable and tunable redox‐active material for sustainable energy technologies.