Synergistic effect of hybrid Cu-activated charcoal matrix on CoO anodes enhances the kinetics and cycling stability of lithium-ion batteries

초록

The advancement of high-performance anode materials for lithium-ion batteries (LIBs) remains a significant challenge because these materials are expected to achieve low cost, high capacity, superior energy density, longterm aging stability, natural abundance, environmental friendliness, and safety. This study addresses this challenge by developing a new ternary CoO-Cu-AC (activated charcoal) composite anode for high-performance LIBs synthesized via a low-cost two-step high-energy ball-milling process. The novel strategy of mechanochemically incorporating electrochemically inactive metallic Cu and fragmented porous AC formed a synergistic integrated framework, which effectively enhanced the electrical conductivity by facilitating rapid charge transfer during cycling, and efficiently buffered volume change of active CoO. These benefits were systematically validated through comprehensive electrochemical characterizations. As a result, the CoO-Cu-AC composite demonstrated better electrochemical performance (cycling and rate performance) compared with CoO-Cu counterpart. In addition, the AC content was meticulously optimized to 20 wt%, leading to high lithium storage performance. The optimized CoO-Cu-AC electrode delivered a high reversible capacity of 770.1 mAh g- 1 at 0.1 A g- 1 after 100 cycles and retained 559.3 mAh g- 1 at 0.5 A g- 1 after 250 cycles, thereby demonstrating the excellent lithium-storage capability and structural stability compared CoO-Cu counterpart.

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