Recently, a team led by Dr. Zhongshuai Wu, a researcher at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, has designed and fabricated two-dimensional ultrathin, high-capacity iron-based zeolitic imidazole framework/graphene (Fe-ZIF/G) nanosheets that match the characteristics of planar energy storage devices. Subsequently, they further utilized a spray-coating method to print flexible, high specific energy planar micro-supercapacitors, and based on this, developed a fully flexible, highly sensitive, self-powered integrated gas sensing microsystem. The related findings were published in Today's Materials.
The development of wearable and flexible microelectronics has stimulated the demand for compatibility, durability, and integration of production, storage, and utilization of energy. Among them, planar micro-supercapacitors feature high power density and rapid charge-discharge characteristics, enabling the collection of surplus electricity generated by energy conversion units anytime and anywhere to power electronic devices. Previously, the team has developed various customizable microenergy systems, such as micro-supercapacitor-gas monitoring systems and integrated self-powered pressure sensing systems. However, to achieve efficient integrated self-powered gas sensing microsystems, there is an urgent need for the development of fabrication techniques highly compatible with energy conversion, storage, and utilization devices, as well as high-performance flexible electrode materials and gas sensing materials.
Printing Process. Supplied by Dalian Institute of Chemical Physics
In this study, the team employed an electrostatic assembly strategy to prepare two-dimensional Fe-ZIF/G heterostructure nanosheets with high specific surface area, ultra-thin structure, and high conductivity, serving as flexible solid-state micro-supercapacitor high-capacitance microelectrode materials. The research found that Fe-ZIF/G heterostructure nanosheets facilitate the transmission of electrolyte ions along the plane, providing abundant electrochemical active sites. The team constructed planar micro-capacitors using spray printing technology, exhibiting a high areal energy density of 9.5 μWh/cm2 and excellent cycling stability. Additionally, the team proposed an integrated design and construction strategy, integrating silicon thin-film solar cells, micro-supercapacitors, and sensors on a co-planar flexible substrate by reducing interfaces between multiple components, developing an integrated, flexible, self-powered planar gas sensing integrated microsystem. The microsystem exhibited high selectivity to ammonia gas response at room temperature and high responsiveness under low ammonia gas concentration conditions.
This work provides a new avenue for the construction of printable self-powered microsystems.
Related paper information: https://doi.org/10.1016/j.mattod.2024.02.006
