Lithium battery "turn over" - the biggest problem in the application of lithium anode

Metallic lithium can be a perfect substitute for graphite, and it is used as a negative electrode material for lithium-ion batteries, so that the latter can solve the problem of "running mileage difference". Recently, the latest achievement of the research group of Associate Professor Jinkui Feng from the School of Materials Science and Engineering of Shandong University was published in the top journal Nano Energy. The introduction of this technology has made lithium batteries, which are regarded as "not suitable for electric vehicle power", ushered in the hope of turning over.

Pure electric vehicles are the focus of the automotive industry. One of the core components of lithium batteries is repeatedly pushed to the cusp of public opinion. It is the biggest complaint point for lithium battery performance and battery life. This stems from the fact that lithium batteries have not seen a significant breakthrough in recent years. It is understood that the commercial battery negative electrode is mainly a lower capacity graphite anode material, which limits the energy density and cruising range of the battery. In contrast, metallic lithium is an ideal lithium battery anode material that can solve its energy density and cruising range.

Jinkui Feng believes that the use of lithium metal as the anode material for lithium-ion batteries mainly needs to overcome two problems: safety and cycle life. The main problem that plagues the metal lithium anode is lithium dendrite. During the cycle, due to local polarization, lithium dendrites are grown on the surface of the metal lithium. When the lithium dendrite grows to a certain extent, it may penetrate the diaphragm. Safety issues, in addition, if lithium dendrites break, it will form "dead lithium", resulting in loss of battery capacity, so lithium dendrites are the biggest obstacle to the application of lithium metal anodes.

Associate Professor Jinkui Feng used vacuum distillation to remove low-boiling metallic zinc from commercial brass to synthesize 3D porous copper and use it as a current collector for lithium metal anodes. Vacuum distillation is a method of obtaining a pure high boiling product by evaporating one or more components of the precursor. The method is environmentally friendly, low cost, and easy to industrialize. The pore diameter and porosity of the prepared porous copper can be regulated by distillation time and temperature, and the produced by-product zinc can be recycled. When the porous copper is used as a metal lithium anode current collector, the growth of lithium dendrites can be suppressed, thereby improving the safety of the battery. It can also alleviate the volume expansion in the circulation process, so as to form a stable SEI film and electrode structure, and obtain good circulation performance and multiplier performance.

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