Soft-Template-Assisted Synthesis of Nano-Sn Anode by Electrodeposition for Lithium-Ion Capacitors: Capacity Balancing for Enhanced Cyclability

Li-ion capacitors (LICs) have emerged as promising energy-storage devices that combine the advantages of electric double-layer capacitors and Li-ion batteries. To realize the optimal LIC performance, the cathode, which is a non-Faradaic-reaction material, should exhibit a high energy density, and the anode, which is a Faradaic reaction material, should exhibit good power density and stability. In this study, we synthesized nano-Sn anode using a soft-template-assisted electrodeposition method as an anode in an LIC. We noted that the depth of discharge (DoD) directly affected the cyclability of the Sn anodes. Furthermore, the capacity balance between the cathode and anode is a key metric for high-performance LIC full-cells. The LIC full-cell assembled with Sn anodes with 12.5% DoD exhibited enhanced cyclability with good discharge capacity and superior Coulombic efficiency of over 98% for 500 cycles compared to that of LIC full-cell prepared with Sn anode with 25% DoD. Thus, our study provides valuable insights into the development of high-performance LICs by demonstrating the importance of precise control of the DoD level of anodes thorough electrochemical impedance spectroscopy.