Kirigami‐Inspired Flexible Lithium‐Ion Batteries via Transformation of Concentrated Stress into Segmented Strain

Abstract

Emerging directions in the growing wearable electronics market have spurred the development of flexible energy storage systems that require deformability while maintaining electrochemical performance. However, the traditional fabrication approaches of lithium‐ion batteries (LIBs) are challenging to withstand long‐cycle bending alternating loads due to the stress concentration caused by the nonuniformity of the actual deformation. Herein, inspired by kirigami, a segmented deformation design of full‐cell scale thin‐type flexible lithium‐ion batteries (FLIBs) with large‐scale manufacturing characteristics via the current collector's mechanical blanking process is reported. This strategy allows the battery's elliptical deformation of the actual state to be transformed into the circular strain of the ideal configuration, thereby dispersing the stress concentration on the top of the battery. According to the results, the designed battery maintains >95% capacity after >20 000 harsh in situ dynamic tests. In addition, finite element analysis further reveals the mechanism that the segmented deformation strategy bears the mechanical stress. This work can enlighten the rational design and customization of electrode patterns for high compatibility with various devices, thereby providing potential opportunities for the application of FLIBs.

Magnetically Driven Powerless Lighting Device with Kirigami Structured Magneto–Mechanoluminescence Composite

“…In Figure 2b,c , results show that the stress distribution was mainly concentrated at the edges of the cuts, similar to other Kirigami geometries. [ 41 , 42 , 43 , 44 ] Under the fixed displacement condition, a fixed stretching displacement of 150 mm was applied to all models and the strain distribution maps of the Kirigami structures were compared. The T and arrow shapes have a smaller area under stress; however, the stress distribution is much more localized, creating stress concentration areas on the edges, whereas the cut shape stress concentration area is wider and more distributed.…”

Strategies for developing flexible lithium batteries with high energy and high safety

“…电池在20000次原位动态变形(沿X方向, 弯曲半径R=27.4 mm, 弯曲180°)和>20000次原位动态变形(沿Y方向, R=30.6 mm, 弯曲120°)后的容量保 持率 [54] . (c) LiFePO 4 正极的剪纸设计1--边裁和剪纸设计2--中心裁及其扭曲和拉伸状态 [55] .…”

“…(b) Schematic illustration of the fabrication process of kirigami FLBs. The capacity retention after 20000 in situ dynamic deformations (X-direction, bending radius R=27.4 mm, bending degree=180°) and after >20000 in situ dynamic deformations (Y-direction, R=30.6 mm, bending degree=120°) [54] . (c) Illustration of the kirigami edge-cut pattern (design 1) and center-cut pattern (design 2) of LiFePO 4 cathodes.…”

Flexible Solid-State Lithium-Ion Batteries: Materials and Structures

“…This cell architecture provides not only excellent flexibility (bending radius ≈ 300 µm), but also high multiplicity (20 A/g) and cycling stability (more than 500 cycles at 1 C with capacity retention over 70%). In addition to the above strategies, origami and kirigami are common strategies for designing 3D FLIBs [104,131]. Origami and kirigami methods are inspired by origami and paper cutting, respectively.…”