Wearable electronics are becoming one of the key technologies in health care applications including health monitoring, data acquisitions, and real-time diagnosis. The commercialization of next-generation devices has been stymied by the lack of ultrathin, flexible, and reliable power sources. Wearable thermo-electrochemical cells (TECs), which can convert body heat to electricity via an electrochemical process, are showing great promise as power sources for such wearable systems. TECs harvest orders of magnitude more voltage per temperature difference (Seebeck coefficient (1-34 mV K −1 )) when compared to the more common thermoelectric generators (Seebeck coefficient ≈tens or hundreds of µV K −1 ). However, there still remain great challenges for TECs progressing towards wearable applications. This review summarizes the recent development of potentially wearable TECs with promise for body-heat harvesting, with a specific focus on flexible electrode materials, solid-state electrolytes, device fabrication, and strategies toward applications. It also clarifies the challenges and gives some future direction to enhance future investigations on high-performance wearable TECs for practical and self-powered wearable devices.

Supercapacitors (SCs), also called electrochemical capacitors, often show high power density, excellent charge/discharge rates, and long cycle life. The recent development of flexible and wearable electronic devices requires that their power sources be sufficiently compact and flexible to match these electronic components. Therefore, flexible SCs have attracted much attention to power current advanced electronics that can be flexible and wearable. In the past several years, many different strategies have been developed to programmably construct different nanocarbon materials into bendable electrode architectures. Furthermore, flexible SC devices with simplified configurations have also been designed based on these nanocarbon‐based architectures. Here, recent developments in the programmable assembly of bendable architectures based on nanocarbon materials are presented. Additionally, the design of flexible nanocarbon‐based SC devices with various configurations is highlighted. The progress made recently paves the way for further development of nanocarbon architectures and corresponding flexible SC devices. Future development and prospects in this area are also analyzed.

In recent years, the extensive application of lithium ion batteries (LIBs) based on LiFePO4 (LFP) cathode in electric vehicles will lead to a large amount of scraped LFP in the...

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Upon immersion of a lithium (Li) anode into a diluted 0.05 to 0.20 M dimethoxyethane-solution of the phosphoric acid derivative (CF 3 CH 2 O) 2 P(O)OH (HBFEP), an artificial solid electrolyte interphase (SEI) is generated on the Li-metal surface. Hence, HBFEP reacts on the surface to the corresponding Li salt (LiBFEP), which is a Li-ion conducting inorganic coordination polymer. This film exhibits -due to the reversibly breaking ionic bonds -self-healing ability upon cycling-induced volume expansion of Li. The presence of LiBFEP as the major component in the artificial SEI is proven by ATR-IR and XPS measurements. SEM characterization of HBFEP-treated Li samples reveals porous layers on top of the Li surface with at least 3 μm thickness. LiÀ Li symmetrical cells with HBFEP-modified Li electrodes show a three-to almost fourfold cycle-lifetime increase at 0.1 mA cm À 2 in a demanding model electrolyte that facilitates fast battery failure (1 M LiOTf in TEGDME). Hence, the LiBFEP-enriched layer apparently acts as a Li-ion conducting protection barrier between Li and the electrolyte, enhancing the rechargeability of Li electrodes.