Bamboo mat-inspired interlocking compact textile electrodes for high-energy-density flexible lithium-ion full batteries

Industrial wearable electronic devices critically require the seamless integration of flexible lithium-ion batteries (LIBs) without compromising high energy density and long cycling stability. Textile-based LIBs show excellent mechanical flexibility but sacrifice energy density and cycling stability. Inspired by the rigid-soft segment structure of bamboo mats, we herein propose the universal design of interlocking compact textile electrodes (ICTEs) for highly flexible LIBs with high energy density and cycling stability. By a simple and scalable pre-rolling treatment, uniform aligned cracks are formed on both sides of the high-packing-density ICTEs, resulting in high areal capacities (4.5 mAh cm−2) and bending stability (20000 bending cycles). In the bending states, the strain of ICTEs is uniformly transferred to the aligned cracks and then released through the interlocking fibers between the aligned cracks. Paired interlocking textile anode and cathode, the soft-packaged full cell exhibits a record-breaking Figure of merit (28.4), high areal and volumetric energy density (11.3 mWh cm−2 and 329 Wh L−1), high capacities retention (∼90%) during 150 charge/discharge cycles and remarkable mechanical robustness (2000 bending cycles at 4.0 mm) under practical conditions. The unique structure design of interlocking compact electrodes provides a promising pathway towards developing high-energy-density flexible LIBs for industrial wearable applications.