posted on 2019-12-17, 22:30authored byYinhua Bao, Guangqi Hong, Ya Chen, Jian Chen, Haosen Chen, Wei-Li Song, Daining Fang
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.