Y. Zhang, S.H. Zheng, F. Zhou, X.Y. Shi, C. Dong, P. Das, J.X. Ma, K. Wang, Z.-S. Wu,*
Small, 2021, 2104506.
DOI: 10.1002/smll.202104506 [PDF]
Pursuing high areal energy density and developing scalable fabrication strategies of micro-batteries are the key for the progressive printed microelectronics.Herein, we report the scalable fabrication of multi-layer printable lithiumion micro-batteries (LIMBs) with ultrahigh areal energy density and exceptional flexibility, based on highly conductive and mechanically stable inks by fully incorporatingthe polyurethane binders in dibasic esters with high-conducting additives of graphene and carbon nanotubes into active materials toconstruct across-linked conductive network. Benefiting fromrelatively higherelectrical conductivity (~7000 mS/cm) and stably connected network of microelectrodes, the as-fabricated LIMBs by multi-layer printing display robust areal capacity of 398μAh/cm2, and remarkable areal energy density of 695μWh/cm2, which are much higher than most LIMBs reported. Further, the printed LIMBs show notable capacity retention of 88% after 3000 cycles, and outstanding flexibility without any structure degradation under various torsion states and folding angles. Importantly, a wearable smart intelligent bracelet, composed of a serially-connected LIMBs pack, a temperature sensor and alight-emitting diode, automatically realized the detection of body temperature. Therefore, this strategy of fabricating highly conductive and mechanically stable printable ink will open a new avenue for developing high-performance printable LIMBs for smart microelectronics.
