Stretchable self-charging energy integrated device of high storage efficiency

Abstract

Integrated energy devices consisting of solar cells and rechargeable batteries are in great demand in wearable electronics and low-energy-density applications in fields such as healthcare. However, developing energy-efficient stretchable energy systems is very difficult due to numerous technical limitations. Herein, a stretchable solar module/rechargeable lithium-ion battery-integrated energy device using a zig-zag truncated electrode for energy storage, nano-sized electrode materials and a polymer–metal-island non-woven common substrate for the integration device is presented. This new stretchable device is portable, has a high operation potential (up to 1.8 V), a long life, high self-charging efficiency, and a high rate-capability. Its self-power conversion/storage efficiency is unprecedented at 13.3%. Additionally, an 89.34% retention capacity can be obtained after 100 cycles, and a surprisingly low-capacity decay of 5.7% in the 30% stretched state is observed. The device's stable performance under various current density and stretching conditions paves the way for the development of highly stretchable integrated energy systems.