The research team of Professor Zhang Qiang from Tsinghua University proposed a composite lithium metal anode in which lithium is melted and impregnated in coral-like carbon fibers in response to the urgent need for metal lithium batteries for composite electrodes. The carbon fiber framework (CF) surface is modified into a lithium-friendly surface by electroplating silver plating so that liquid molten metal lithium can be quickly adsorbed into the silver-plated carbon fiber framework (CF/Ag), so a high-performance composite lithium metal anode (CF/Ag) can be obtained. Ag-Li).
On the one hand, the silver coating can modify any conductive framework into a lithium-friendly conductive framework that can siphon liquid molten lithium; a cyclic form of "dead lithium". In situ, metal lithium deposition experiments found that this composite structure is difficult to form dendrites. The proposed composite lithium metal anode can be stably cycled for more than 160 cycles under extremely harsh conditions of 10 mA cm-2 and 10 mAh cm-2 with extremely low polarization. Compared with traditional metal lithium anodes, composite lithium metal anodes can withstand the limit of areal current density and areal capacity cycling, showing high safety characteristics.
Coral-like carbon fiber melt-impregnated lithium composite lithium metal anode
The composite metal lithium negative electrode is directly assembled with the sulfur positive electrode and the lithium iron phosphate positive electrode to form a lithium-sulfur battery and a lithium iron phosphate battery with excellent performance. Its lithium iron phosphate battery can be stably cycled for more than 500 times at a rate of 1.0C, while the initial discharge capacity of a lithium-sulfur battery at 0.5C can reach g-1, and maintain a high capacity cycle for longer than 400 cycles. The conductive framework silver-plated lithium filling method in this work is generally applicable to the design and preparation of any composite metal lithium anode based on the conductive framework. Lithium” cycle appears, and then obtains excellent electrochemical performance in full battery systems such as lithium-sulfur batteries, and improves the safety of energy storage systems.
Zhang Qiang's lithium-sulfur battery.