3D Printing of Flexible Electrodes Towards Wearable Lithium Ion Battery

A novel method to fabricate flexible free-standing electrodes with textile structure for lithium-ion batteries was provided by applying extrusion-based three-dimensional (3D) printing technology. Meanwhile, highly concentrated poly(vinylidene fluoride) (PVDF) is used as viscosity modifier, carbon nanotube (CNT) as conducting additive, and lithium iron phosphate (LFP) or lithium titanium oxide (LTO) as cathode or anode active materials respectively to develop printable inks with obvious shear-thinning behavior, and with the apparent viscosity and storage modulus platform value of over 10(5) Pa . s, which is beneficial to the printability and enable complex 3D structures solidification. The electrochemical test shows that both printed electrodes have similar charge and discharge specific capacities under current density of 50mA . g(-1). To explore the feasibility of the printed electrodes, a pouch cell with as-printed LFP and LTO electrode as cathode and anode respectively is assembled. The pouch cell without deformation delivers discharge specific capacities of approximately 108mAh . g(-1), and there is a tiny increase in discharge specific capacities of around 111mAh . g(-1) for bended pouch cell.