Three-dimensional printed lithium iron phosphate coated with magnesium oxide cathode with improved areal capacity and ultralong cycling stability for high performance lithium-ion batteries

Three-dimensional (3D) printing of Li-ion batteries with unconventional 3D electrodes has attracted considerable attention in recent years. However, fabricating 3D electrodes with high specific capacity, high areal capacity, ultralong cycling stability, and improved rate performance remains a challenge to date. Novel 3D grid-patterned LiFePO4@MgO composite electrodes with thicknesses of 143, 306, and 473 μm were fabricated via 3D printing. The electrochemical performance of half cells was evaluated. The 3D-printed LiFePO4@MgO (143 μm) electrodes exhibit stable specific capacities of 142.8 mAh g-1 @ 1.0 C and 90.3 mAh g-1 @ 10.0 C after 800 and 1700 cycles, respectively. In addition, the 473 μm-thick 3D grid-patterned LiFePO4@MgO achieves an areal capacity of 3.01 mAh cm-2 @ 0.1 C after 20 cycles. The full cells comprised 143 μm-thick 3D-printed LiFePO4@MgO, and 217 μm Li4Ti5O12 electrodes show a capacity of 139.0 mAh g-1 @ 1.0 C after 400 cycles. These results indicate that, this type of thick 3D-printed LiFePO4@MgO electrode achieves high capacity, high-rate capability, and ultralong cycle stability. The outstanding performance ascribes the fast electrolyte infusion of 3D-printed electrodes and the enhanced electronic/ionic transport.