Exploring MXene-based micro-supercapacitors for energy storage in wearable electronics

Over the past several years, wearable electronics have exploded in popularity due to their applications in consumer electronics and health monitoring. This technology has created a need for compatible energy storage devices capable of supplying power while remaining resistant to physical deformations. Micro-supercapacitors (MSCs) are promising candidates, exhibiting high power densities, long lifespans, and fast charging times.

Dai et al. discussed recent advances in MXene-based MSCs, compared alternate configurations, highlighted existing challenges in the field, and identified directions for future research.

“MXenes are regarded as promising electrode materials for MSCs due to their metal-like conductivity, high specific surface area, good hydrophilicity, and surface chemical tunability,” said author Mingzai Wu. “However, the mechanical stiffness of 2D layered structures presents a challenge for the direct implantation of MXene electrodes in deformable MSCs.”

The authors highlighted two alternate MXene structures: 1D fiber-shaped structures and 2D planar structures. The former can be woven into nearly any shape to provide stable power under multiple strain conditions, while the latter exhibits high areal energy density and can be integrated into other microelectronic devices for better miniaturization.

The researchers also discuss the current shortcomings of MXene-based stretchable MSCs, such as the low areal energy density, poor electrolyte stretchability and voltage window, and lack of reasonable device configurations. They are hopeful that future work will address these problems and expand the material’s capabilities.

“We are looking forward to MXene-based stretchable MSCs that not only have high energy efficiency and mechanical stretchability, but also possess some novel functions such as self-charging, self-healing, and biodegradability,” said Wu.

Source: “Recent progress of stretchable MXenes based micro-supercapacitors,” by Peng Dai, Wen Zhang, Tongtong Jiang, Ying Xiong, and Wu Mingzai, APL Materials (2023). The article can be accessed at https://doi.org/10.1063/5.0152042 .