High performance stretchable Li-ion microbattery

Abstract The recent advances in wearable technologies had caused a surge in the demand for stretchable Li-ion microbatteries. Herein, a special design based on micropillar electrodes supported on metallic serpentines has been investigated to achieve the fabrication of a functionning device. Besides achieving high areal capacity values like 2.5 mA h cm−2 at C/10 (i.e. 0.07 mA cm−2), the micropillars make the system reversibly stretchable. Electrochemical tests revealed excellent performance when the stretchable micropower source was subjected to different mechanical strains. Indeed, 73% of the capacity is retained over 100 cycles under 30% strain and all fatigue tests showed that capacity retention remain higher than 70%.