Laser-Assisted Patterning of 2D/1D WS2/CNT Electrodes for All-Solid-State In-Plane Microsupercapacitors with Improved Rate Performance

Abstract

Microsupercapacitors (MSCs) based on high-performance electrode nanomaterials are considered alternative power sources capable of meeting the growing needs of miniaturized electronic devices. Tungsten disulfide (WS₂) nanosheets, with their large surface area and pseudocapacitive nature, serve as potential building blocks for MSC device fabrication. However, the poor electrical conductivity of semiconducting 2H WS₂ nanosheets hinders electron transport, thereby limiting the specific capacitance and rate performance of the resulting MSCs. In this study, we report the fabrication of laser-scribed all-solid-state high-rate MSCs by incorporating carbon nanotubes (CNTs) into liquid-exfoliated WS₂ nanosheets. The optimized MSC device (WS₂/CNT5) exhibits an areal capacitance of 6.8 mF cm^–2 at 100 μA cm^–2, with an excellent cyclic stability of 88.9% after 1000 cycles. Notably, the CNT-incorporated devices, WS₂/CNT5 and WS₂/CNT10, demonstrate substantial enhancements in rate capability, with 74% and 91% retention, respectively, compared to the pristine WS₂-based device. Additionally, the WS₂/CNT5 MSC demonstrates excellent energy and power densities of 0.94 μW h cm^–2 and 0.05 mW cm^–2. These results can be attributed to the formation of a conductive 1D CNT network within the 2D WS₂ structure, which facilitates fast electron transport. We believe this strategy can be extended to other synergistic 2D/1D nanocomposites for scalable and facile fabrication of high-rate MSC devices.