Design of high-capacity composite anode for next generation lithium-ion batteries

초록

Ga is in primary focus for high-capacity anodes of Li-ion batteries (LIBs). Ga-based anode can form Li2Ga with Li at room temperature. Again, decoupling of Li and Ga is easy compared to other high-capacity materials like Si. Low melting temperature, volume changes, and particle agglomeration of Ga-based electrodes in lithiation and delithiation processes are serious challenges toward its commercialization. To overcome these obstacles, we propose a new composite using Mn-doped GaFeP engineered on N-rGO. Three Mn doping ratios (1, 5, and 10 %) were studied for optimization of electrochemical performance. We observed that the 5 % Mn-doped GaFeP/NrGO delivered an impressive reversible capacity of 1099.9 mAh/g after 200 cycles at 0.3 A/g. Its retention rate capacity (97.6 %) was higher than those of other electrodes. Furthermore, an excellent rate performance and substantial long-term stability of 671.9 mAh/g was achieved at 1.5 A/g after 850 cycles. The reaction mechanism of the high-performance composite electrode is expounded. We hope our study provides new insights and guidelines to the development of Mn-doped Ga-based electrodes with high capacities, minimal volume change, and long cycle stabilities for next-generation LIBs.

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