(a) The structure of one single IHMEGdevice with asymmetric-moisturepenetration layers. The material consistsof PA-gelated hydrogel. (b) The schematic diagram of the asymmetric moisture stimulus-induced potential in IHMEG. (c) The continuous DC open-circuit voltage output (red curve) of anIHMEGdevice over time under open
Power devices by integration of IHMEGunits in serial or parallel packages as a practical DC source for commerciallow-powerelectronics
The applications of IHMEGs as a direct power source
In the context of global resource shortage and high demand for carbon neutrality, it is of great significance to find simple and efficient green energy conversion technology to achieve sustainable development of energy and society. Moisture-electric generator (MEG) is based on the chemical energy from atmospheric moisture to generate electricity directly, without the generation of pollutants and harmful gas emissions, which is an emerging research focus in the energy field. However, most MEGs suffer from intermittent electrical signals and low current. In addition, the realization of large-scale integration and practical applications is still the bottleneck of current research.
To address this issue, Prof. Xiaoming Tao’s research team has developed a novel and efficient ionic hydrogel moisture-electric generator (IHMEG), which converts the energy released by captured moisture in the air into electricity, realizing efficient current density and power output. A single IHMEG unit of 0.25 cm2 can continuously generate direct-current electricity with a constant open-circuit voltage of ~0.8 V for over 1000 hours, a high short-current density of 0.24 mA·cm-2 and power density of up to 35 mW·cm-2. Of great importance is that large-scale integration of IHMEG units can be readily accomplished to offer a high voltage of up to 210 V, making the flexible IHMEG assembly capable of directly driving numerous commercial electronics, including electronic ink screen, metal electrodeposition setup and even light-emitting-diode arrays. This IHMEG device with high cost-efficiency, easy-to-scaleup fabrication and high power-output opens a brand-new perspective to develop a green, versatile and efficient power source for Internet-of-Things and wearable electronics. The work is published in Advanced Materials (https://doi.org/10.1002/adma.202200693) recently. The first author is a PhD graduate, Dr. Yang Su.
