General approach for high-power Li-ion batteries: Multiscale lithographic patterning of electrodes

Abstract

We demonstrate multiscale patterned electrodes that provide surface-area enhancement and strong adhesion between electrode materials and current collector. The combination of multiscale structured current collector and active materials (anodes and cathodes) enables us to make high-performance Li-ion batteries (LIBs). When LiFePO4 (LFP) cathode and Li4Ti5O12 (LTO) anode materials are combined with patterned current collectors, their electrochemical performances are significantly improved, including a high rate capability (LiFePO4: 100 mAh g-1, Li4Ti5O12: 60 mAh g-1 at 100C rate) and highly stable cycling (LiFePO4: capacity retention of 99.8% after 50 cycles at 10C rate). Moreover, we successfully fabricate full cell system consisting of patterned LFP cathode and patterned LTO anode, exhibiting high-power battery performances [capacity of approximately 70 mAh g-1 during 1000 cycles at 10C rate (corresponding to charging/discharging time of 6 min)]. We extend this idea to Si anode that exhibits a large volume change during lithiation/delithiation process. The patterned Si electrodes show significantly enhanced electrochemical performances, including a high specific capacity (825 mAh g-1) at high rate of 5C and a stable cycling retention (88% after 100 cycle at a 0.1C rate). This simple strategy can be extended to other cathode and anode materials for practical LIB applications.