High-performance LiFePO4 and SiO@C/graphite interdigitated full lithium-ion battery fabricated via low temperature direct write 3D printing

Abstract

Lithium-ion batteries (LIBs) composed of thin tape–casted electrodes face some intrinsic challenges especially the trade-off between energy density and power density. Three-dimensional (3D) structural batteries fabricated by 3D printing have the potential to overcome this challenge. Silicon oxide–based materials are promising candidates for the next-generation high-performance LIBs. In this study, interdigitated full batteries composed of comb-like LiFePO4 3D cathodes and comb-like SiO@C/graphite 3D anodes are fabricated via low temperature direct writing 3D printing process. The 3D printing at a low temperature of below −20 °C enables the 3D-printed SiO@C/graphite electrodes obtain a high porosity of ∼60% and tri-modally hierarchical porous microstructure. Comb-like 3D SiO@C/graphite anodes with the thickness of ∼418 μm, ∼692 μm, and ∼806 μm and corresponding mass loading of ∼39.2 mg cm-2, ∼60.9 mg cm-2, ∼84.3 mg cm-2, respectively, are fabricated to evaluate their electrochemical performance. These thick 3D electrodes display impressive areal capacities of ∼17.9, ∼26.7, and ∼33.2 mA h cm-2 @ 0.3 C depending on their electrode thickness. Coupled with comb-like LiFePO4 3D cathodes, interdigitated full batteries with two N/P ratios of 0.91 and 0.82 are fabricated. These full batteries exhibit high energy density, high power density, and stable cycling performance.