Aqueous asymmetric pseudocapacitor featuring high areal energy and power using conjugated polyelectrolytes and Ti3C2Tx MXene

作者：Benjamin Rui Peng Yip, Chaofan Chen, Yan Jiang, David Ohayon, Guillermo C. Bazan, Xuehang Wang · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-63034-9 · 被引用次数：27 · 研究领域：MXene and MAX Phase Materials、Supercapacitor Materials and Fabrication、Advanced Sensor and Energy Harvesting Materials

Despite the development of various pseudocapacitive materials, full-cell pseudocapacitors have yet to surpass the power density of conventional electric double layer capacitors, primarily due to the lack of high-rate positive pseudocapacitive materials. This work reports a solid-state conjugated polyelectrolyte that achieves high-rate charge storage as a positive electrode, facilitated by a co-ion desorption mechanism. The conjugated polyelectrolyte retains 70% of its capacitance at 100 A g−1 with a mass loading of 2.8 mg cm−2 and exhibits a long cycling life of 100,000 cycles in a Swagelok cell configuration. Increasing the electrode thickness fourfold has minimal impact on ion diffusivity and accessibility, yielding a high areal capacitance of 915 mF cm−2. When paired with a high-rate negative pseudocapacitive electrode Ti3C2Tx, the device leverages the redox-active potentials of both materials, achieving a device voltage of 1.5 V and supports operation rates up to 10 V s−1 or 50 A g−1. This configuration enables the pseudocapacitor to deliver an areal power of 160 mW cm−2, while significantly increasing the areal energy (up to 71 μWh cm−2). The high areal performance, combined with the additive-free and water-based fabrication process, makes pseudocapacitors promising for on-chip and wearable energy storage applications. Pseudocapacitors are emerging as alternatives to conventional supercapacitors. Here, authors showed an uncommon charge storage mechanism in a high-rate co...