Customized Kirigami Electrodes for Flexible and Deformable Lithium-Ion Batteries

Customized deformable lithium-ion batteries (LIBs) have attracted interest in the emerging power systems for flexible and wearable electronics. However, a key challenge for developing these batteries is the fabrication of customized deformable electrodes that exhibit strong mechanical tolerance and robust electrochemical performance during deformation. Here, free-standing customized kirigami electrodes for deformable LIBs are fabricated by an evolutionary printing method with universal viscous electrode inks and a customizable polydimethylsiloxane template. The electrodes comprise lithium iron phosphate or lithium titanium oxide nanoparticles with a conductive carbon nanotubes/poly(vinylidene fluoride) scaffold, which is ideal for electron transfer. The compact microstructure and kirigami pattern endow the electrodes with superior mechanical robustness (over 500 stretch-release cycles) and resistance stability both in unstretched and stretched states. Finite element analysis and corresponding experiment tests reveal ultralow strain inside the materials, showing less than 3% strain even under 100% stretch ratio. With 500-times stretched electrodes, the full-cell LIBs can still deliver a considerable discharge capacity of average 94.5 mA h g^-1 at 0.3 C after 100 discharge/charge cycles. The integration of such outstanding mechanical stability, excellent electrochemical performance, and simple printing method with accessible starting materials presents promising opportunities for customizing deformable components for flexible energy storage devices.