Nanoarchitectured In-situ Pre-Lithiated Carbon Anode for High-Power and Long-Life Li-Ion Capacitors

Abstract

Lithium-ion capacitors (LICs) combine high energy and power densities but often suffer from poor cycle stability (<10,000 cycles) due to uncontrolled Li+ ion losses during solid electrolyte interphase (SEI) layer formation and irreversible side reactions. From the industrial standpoint, achieving >20,000 cycles necessitates an adequate pre-lithiation strategy that efficiently replenishes ions to offset such losses. This work proposes a scalable pre-lithiation approach by adding a thin lithium metal foil (46 µm) in direct contact with the anode while assembling LIC. The electrochemical potential difference between the Li foil and the carbon-coated porous current collector anode facilitates the lithiation process and promotes in-situ pre-lithiation (ISP). After a 10 h pre-lithiation time, the resultant LiCx and SEI layer were verified by ex-situ characterizations. The optimized LIC demonstrated a best-in-class specific energy of 204 Wh kg-1 and a specific power of 5.5 kW kg-1. The device achieved a remarkable capacity retention of 87 % after 40,000 full charge-discharge cycles, equivalent to 631 h. This structurally engineered strategy underscores the critical role of pre-lithiation in advancing the next-generation, high-performance energy storage solutions.