Hygroscopic-thermoelectric synergistic design of electronic device heat dissipation systems: integration study on passive heat dissipation and energy conversion

Abstract

With the rapid development of high-performance electronic devices towards higher integration and power density, thermal management has become a critical challenge, entailing intense heat dissipation needs and leaving a large amount of low-grade waste heat unrecovered. Traditional heat dissipation and energy conversion technologies often serve a single function, struggling to address the dual challenges of efficient heat dissipation and energy recovery. To tackle this, this study develops a fin-felt composite device with a self-sustaining moisture cycle, which builds upon a conventional heat sink by integrating hygroscopic cooling technology and water evaporation induced power generation technology, thereby enhancing heat dissipation efficiency while simultaneously enabling the conversion of low-grade energy into electricity. Experimental results show that under a heat flux of 25 000 W m⁻², the composite device reduces temperature by 41.6 °C compared to traditional air-cooled heat sinks. Driven by waste heat, the power generation of a single activated carbon felt is increased by over 70%. Through the optimization of double-sided electrodes and multi-unit integration, the system enables rapid charging of supercapacitors, drives micro-fans, and supplies continuous power to lithium batteries, while demonstrating good stability in cyclic tests. This work presents an efficient and integrated synergistic solution for heat dissipation and low-grade energy conversion in electronic devices.