High gravimetric and volumetric energy densities enabled by 3D-printed thick anode

Abstract

Developing advanced Li-ion batteries with high areal capacity, and gravimetric and volumetric energy densities remains a challenge. This study uses additive manufacturing technology to prepare thick Li₄Ti₅O₁₂-Li₄SiO₄ (LTO-LSO) composite electrodes for Li-ion batteries with high area capacity and energy density. The 3D-printed electrodes are made of grid-patterned and closely stacked LTO-LSO composite, carbon black super p, and PVDF. The LSO nanoparticles are uniformly wrapped on the surface of LTO as a protective layer, resulting in increased ionic/electronic conductivity and abundant open and hierarchical macropores in the planned grid-lined 3D-printed LTO-LSO electrodes. The composite electrode has excellent conductivity (up to 4.13$\times$10² μS cm⁻¹) and low charge-transfer resistance, making it suitable for 3D-printed thick electrodes. The 3D-printed thick LTO-LSO composite electrodes (12 layers) have a high areal capacity of 6.56 mAh cm⁻², areal and volumetric energy densities of 388.04 mWh cm⁻² and 241.46 mWh cm⁻³, as well as excellent cycling performance at 10C after 450 cycles. Moreover, the full cell with a 3D-printed thick LTO-LSO anode and 3D-printed LiCoO₂ (LCO) cathode exhibits exceptional cycle stability, gravimetric and volumetric energy densities of 723.40 Wh kg⁻¹ and 1200 Wh L⁻¹, respectively. Our strategies show that growing a highly conductive protective layer on the surface of electrodes and designing ultrathick electrodes are promising approaches to the fabrication of multidimensional structures with high area capacity, gravimetric and volumetric Li-ion batteries.