3D-printed grid LiFePO₄@ACB cathode for Li-ion batteries with high energy and areal density

Abstract

Despite great efforts that have been devoted to high-performance lithium-ion batteries, conventional electrode fabrication methods still face the challenge of low areal capacity and limited energy density required for electric vehicle applications. In this work, LiFePO4@ACB (acetylene carbon black), denoted as ACB cathodes, were designed with a porous structure utilizing direct ink writing 3D-printing (3D) technology for enhanced areal specific capacity and energy density in lithium-ion batteries (LIBs). The 3D-printed composite cathodes consist of closely packed and well-aligned LiFePO4@ACB filaments. ACB particles are wrapped on the outer surface of olivine LiFePO4, which contributes to the formation of hierarchical and abundant open pores. The 3D-printed LiFePO4@ACB cathodes exhibited a higher capacity, enhanced cycling life, and high areal specific capacity compared to those of conventional ink-cast thick LiFePO4@ACB cathodes. Grid-patterned 3D-printed LiFePO4@ACB (12 layers) exhibited an enhanced areal specific capacity of 6.7795 mAh cm−2 and high specific energy density of 634.372 Wh kg−1 at a specific power density of 59.95 W kg−1, due to its short ion transport pathways and enhanced mechanical strength. This work demonstrates that the direct ink writing strategy enables the fabrication of grid-patterned electrodes with high areal and energy densities, offering significant potential for the future development of high-performance lithium-ion batteries.