LAUSR

Solar induced thermal energy is a vital heat source supplementing body heat to realize thermo-to-electric energy supply for wearable electronics. Thermo-electrochemical cells (TECs), compared to the widely investigated thermoelectric generators (TEGs), show greater potential in wearable applications due to the higher voltage output from low-grade heat and the increased option range of cheap and flexible electrode/electrolyte materials. In this work, a wearable photo-thermo-electrochemical cell (PTEC) is firstly fabricated through the introduction of a polymer-based flexible photothermal film as a solar-absorber and hot electrode, followed by a systematic investigation of wearable device design. The as-prepared PTEC single device shows outstanding output voltage and current density of 15.0 mV and 10.8 A m-2 , 7.1 mV and 8.57 A m-2 , for the device employing p-type and n-type gel electrolytes, respectively. Benefiting from the equivalent performance in current density, a series connection containing 18 pairs of p-n PTEC devices is effectively made, which can harvest solar energy and charge supercapacitors to above 250 mV (1 sun solar illumination). Meanwhile, a watch-strap shaped flexible PTECs (8 p-n pairs) that can be worn on a wrist is fabricated, and the realised voltage above 150 mV under light shows the potential for use in wearable applications. This article is protected by copyright. All rights reserved.