Researchers Develop Semi-liquid Metal Anodes To Increase Lithium Battery Capacity By 10 Times

- Aug 20, 2019-

According to foreign media reports, researchers at Carnegie Mellon University's Mellon Institute of Technology have developed a semi-liquid lithium metal anode that provides a new paradigm for battery design.

Lithium batteries made with such new electrodes will have higher capacity and are safer than conventional lithium metal batteries made of aluminum foil as anodes.

Lithium batteries have the ability to store large amounts of energy and are therefore one of the most common types of rechargeable batteries in modern electronics. Generally, such batteries consist of a flammable liquid electrolyte and two electrodes (anode and cathode), wherein the anode and cathode are separated by a membrane. After repeated charge and discharge of the battery, lithium dendrites will grow on the surface of the electrode. Such dendrites will pierce the film separating the two electrodes, thereby bringing the cathode into contact with the anode. As a result, the battery may be short-circuited. Worst, it may be Get angry.

Krzysztof Matyjaszewski, professor of natural sciences at the Department of Chemistry at Carnegie Mellon University, said: "In theory, the use of lithium metal anodes in lithium batteries is much larger than that of graphite anodes, but the most important thing is to ensure batteries. It is safe."

Currently, volatile liquid electrolytes are used in batteries. One of the solutions is to use solid ceramic electrolytes, which are highly conductive, non-flammable, and sufficiently strong against dendriticity. However, the researchers found that the contact between the ceramic electrolyte and the solid lithium anode was insufficient to store and supply the power required by most electronic products. Sipei Li, a Ph.D. student in the Department of Chemistry at Carnegie Mellon University, and Han Wang, a Ph.D. student in the Department of Materials Science and Engineering at Carnegie Mellon University, have developed a new material, a semi-fluid metal anode, to overcome this shortcoming.

Li and Wang collaborated with Matyjaszewski and Jay Whitacre to create a biconducting polymer/carbon-based composite with lithium particles evenly distributed over it. The carbon-based composite material is capable of maintaining flow at room temperature so as to be in sufficient contact with the solid electrolyte. By combining a semi-liquid metal anode with a garnet solid ceramic electrolyte, the energy density of such a battery can be increased by a factor of 10 compared to a battery made using a solid electrolyte and a conventional lithium foil anode, thereby making such a battery more conventional than conventional batteries. The life cycle of the battery is also longer.

Researchers believe that their approach can have far-reaching implications, such as the ability to produce high-capacity batteries for electric vehicles and the manufacture of specialized batteries for wearable devices that require flexible batteries. Moreover, the researchers also believe that their methods can be used in other rechargeable battery systems, such as nano metal batteries and potassium metal batteries, as well as for grid energy storage systems.