General approach for high-power li-ion batteries: multiscale lithographic patterning of electrodes

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 Li4 Ti5 O12 (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) , Li4 Ti5 O12 : 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.