Stretchable batteries with self-similar serpentine interconnects and integrated wireless recharging systems

Abstract

An important trend in electronics involves the development of materials, mechanical designs and manufacturing strategies that enable the use of unconventional substrates, such as polymer films, metal foils, paper sheets or rubber slabs. The last possibility is particularly challenging because the systems must accommodate not only bending but also stretching. Although several approaches are available for the electronics, a persistent difficulty is in power supplies that have similar mechanical properties, to allow their co-integration with the electronics. Here we introduce a set of materials and design concepts for a rechargeable lithium ion battery technology that exploits thin, low modulus silicone elastomers as substrates, with a segmented design in the active materials, and unusual 'self-similar' interconnect structures between them. The result enables reversible levels of stretchability up to 300%, while maintaining capacity densities of B1.1 mAh cm À 2 . Stretchable wireless power transmission systems provide the means to charge these types of batteries, without direct physical contact.

Fiber‐Type Solar Cells, Nanogenerators, Batteries, and Supercapacitors for Wearable Applications

“…Device design which includes the selection of flexible and bendable components such as the electrodes are the key factors that affect the stability and efficiency of these devices. Buckling or fracture structured metallic films or conducting polymers are used on elastic substrates as the electrodes to achieve ultimate stretchability 50, 51, 52, 53, 54, 55, 56. Yang et al57 developed a unique method to develop elastic electrically conducting fibers for their stretchable, wearable photovoltaic devices which maintained a PCE as high as 7.13% under stretching.…”

“…c) Aspects in battery layout and design. Reproduced with permission 51. Copyright 2013, Springer Nature.…”

“…For example, a wearable device such as an epidermal sensor requires a stretchable energy device to power the sensing functionalities. Xu et al fabricated a stretchable, rechargeable battery on a silicone elastomer with segmented layouts and iterative interconnection in similar geometries 51. The structure of the battery is shown in the Figure 13c.…”

Biomimicking Topographic Elastomeric Petals (E‐Petals) for Omnidirectional Stretchable and Printable Electronics

“…The booming of research in ultraflexible, stretchable, and wearable electronics in the past decade has witnessed the remarkable development of advanced materials,1, 2, 3 structures,4, 5, 6, 7, 8, 9 and devices10, 11, 12, 13, 14, 15, 16, 17, 18, 19 that can function under large tensile strains (1%). In particular, the realization of highly conductive and stretchable metal interconnects, contacts, and electrodes are recognized as one critical milestone for these thin film devices 2, 13, 20, 21, 22, 23, 24.…”

“…In particular, the realization of highly conductive and stretchable metal interconnects, contacts, and electrodes are recognized as one critical milestone for these thin film devices 2, 13, 20, 21, 22, 23, 24. Conventionally, metals are considered as rigid and nonstretchable materials due to their high Young's modulus, e.g., >100 GPa in the case of Cu 25.…”