Meimei Yu

The electrolyte-wettability of electrode materials in liquid electrolytes plays a crucial role in electrochemical energy storage, conversion systems, and beyond relied on interface electrochemical process. However, most electrode materials do not have satisfactory electrolyte-wettability for possibly electrochemical reaction. In the last 30 years, there are a lot of literature have directed at exploiting methods to improve electrolyte-wettability of electrodes, understanding basic electrolyte-wettability mechanisms of electrode materials, exploring the effect of electrolyte-wettability on its electrochemical energy storage, conversion, and beyond performance. This review systematically and comprehensively evaluates the effect of electrolyte-wettability on electrochemical energy storage performance of the electrode materials used in supercapacitors, metal ion batteries, and metal-based batteries, electrochemical energy conversion performance of the electrode materials used in fuel cells and electrochemical water splitting systems, as well as capacitive deionization performance of the electrode materials used in capacitive deionization systems. Finally, the challenges in approaches for improving electrolyte-wettability of electrode materials, characterization techniques of electrolyte-wettability, as well as electrolyte-wettability of electrode materials applied in special environment and other electrochemical systems with electrodes and liquid electrolytes, which gives future possible directions for constructing interesting electrolyte-wettability to meet the demand of high electrochemical performance, are also discussed.

Abstract In recent years, the development of implantable bioelectronics has garnered significant attention. With the continuous advancement of IoT and information technology, implantable bioelectronics can be utilized more effectively for health monitoring to enhance treatment outcomes, reduce healthcare costs, and improve quality of life. Implantable energy storage devices have been widely studied as critical components for energy supply. Conventional power sources are bulky, inflexible, and potentially contain materials that are dangerous to the body. Meanwhile, human tissues are soft, flexible, dynamic, and closed, which puts new requirements on energy storage devices to improve the safety, stability, and matching of implantable batteries or supercapacitors. Herein, recent advances in state‐of‐the‐art nonconventional power options for implantable electronics, specifically biocompatible, miniaturized, stretchable/deformable, biodegradable/bioresorbable, edible, and injectable energy storage devices, are reviewed in this paper. The material strategy and architectural design of the next‐generation implantable energy storage device are discussed, including the selection principle of electrolytes, the all‐in‐one structure design strategy, and the way to realize self‐charging. Finally, the challenges and prospects of emerging design strategies toward developing next‐generation implantable batteries and supercapacitors for the future are put forward.

Abstract With the development of flexible and wearable electronic devices, it is a new challenge for polymer hydrogel electrolytes to combine high mechanical flexibility and electrochemical performance into one membrane. In general, the high content of water in hydrogel electrolyte membranes always leads to poor mechanical strength, and limits their applications in flexible energy storage devices. In this work, based on the “salting out” phenomenon in Hofmeister effect, a kind of gelatin‐based hydrogel electrolyte membrane is fabricated with high mechanical strength and ionic conductivity by soaking pre‐gelated gelatin hydrogel in 2 m ZnSO 4 aqueous. Among various gelatin‐based electrolyte membranes, the gelatin‐ZnSO 4 electrolyte membrane delivers the “salting out” property of Hofmeister effect, which improves both the mechanical strength and electrochemical performance of gelatin‐based electrolyte membranes. The breaking strength reaches 1.5 MPa. When applied to supercapacitors and zinc‐ion batteries, it can sustain over 7500 and 9300 cycles for repeated charging and discharging processes. This study provides a very simple and universal method to prepare polymer hydrogel electrolytes with high strength, toughness, and stability, and its applications in flexible energy storage devices provide a new idea for the construction of secure and stable flexible and wearable electronic devices.