Stretchable Silver‐Zinc Batteries Based on Embedded Nanowire Elastic Conductors

With the continuous progress of the energy use and demand, functionalized energy storage and conversion devices (ESCDs) are urgently needed. In the meantime, stretchable ESCDs are attracting intensive attention due to their great potential for specific applications, such as wearable electronics, an electronic skin, implant electronics, and other collapsible gadgets. Design and synthesis of nanomaterials are at the core in the development of highly stretchable supercapacitors, batteries, and solar cells for such applications. This chapter first provides a brief summary of research development on the stretchable ESCDs in the past decade through various strategies of device design and manufacturing approach. After that, the focuses are on the advanced engineering of nanomaterials as active materials to achieve the stretchability of these ESCDs while maintaining a stable and functional performance. Finally, some of the challenges and the important directions in the areas of design and synthesis of nanomaterial facing the stretchable ESCDs are discussed concisely. IntroductionWith the rapidly increasing population and economic development, the world's energy consumption is escalating dramatically, resulting in one of the most serious global challenges of our time-energy scarcity. Hence, a crowd of research in the areas of advanced technologies for energy storage (e.g., batteries and supercapacitors) and conversion (e.g., solar cells) during the past decade has been driven by the

The development of ultra‐compliant power sources is crucial for their seamless integration with next‐generation skin‐like wearable and implantable biomedical systems for long‐term health monitoring. Toward this goal, stretchable energy storage and conversion devices (ESCDs), including supercapacitors, lithium‐ion batteries (LIBs), solar cells, and generators are now attracting intensive worldwide research efforts. The purpose of this review is to discuss the latest achievements in the development of such stretchable energy devices in the context of biomedical applications. We first review the viable strategies and methodologies of fabricating stretchable energy storage and conversion devices. Then, we focus on description of various types of soft energy devices from a materials point of view. Furthermore, we discuss the challenges and opportunities in the design of truly conformal soft energy systems, including various key parameters, such as energy density, stability, and scalability.

A novel asymmetric separator with high electrolyte wettability and chemical stability was developed for alkaline batteries. This separator was fabricated from an electrolyte-absorbing layer (cellulose nonwoven, CN) and an alkali-resistant layer (PVdF-ZrO 2 matrix), which were integrated together by a point-bonded method using polyvinyl alcohol fibers as the binder. The characteristic properties of the composite separator have been studied by structural characterization, contact angle testing, weight and dimensional stabilities, electrolyte-absorbing rate, and electrochemical behavior. Results showed that the composite separator had a uniform surface morphology and highly gradient three-dimensional porous structure, which led to a low electrolyte contact angle of 35 and an area electrical resistance of 0.08 U cm 2 . Moreover, it showed a low weight reduction rate of 7.5% and an area shrinkage rate of 2.0% in 40 wt% KOH solution at 333 K for 120 h. Due to the electrolyte-philic macroporous layer, the composite separator exhibited a high electrolyte-absorbing rate, which was higher than 55 mm for 5 min. These characteristics endowed the composite separator with excellent electrochemical performance, including a short activation time and a long dry/wet storage life. It is demonstrated that the composite separator can be a good candidate for alkaline batteries, especially for self-activated zinc-silver oxide batteries.