In recent years, renewable energy has developed rapidly around the world, and large-scale energy storage technology is the key core technology to solve the problem of renewable energy grid-connected power generation. Chinese Academy of Sciences Ningbo material researchers have made important progress in the research of water ion batteries. For the first time, they have proposed a new concept of using lithium-sodium mixed ion electrolyte to construct a new type of water ion batteries. The related research results were published in the "Science Report".
The traditional lithium ion battery using an organic solvent as an electrolyte has a high energy density, but has the problems of low safety and high cost. In contrast, water-based ion batteries have the advantages of low price, no environmental pollution, and high safety, and have potential important application prospects in large-scale energy storage systems. However, the electrode materials currently suitable for aqueous sodium ion batteries are extremely scarce, which has become a bottleneck hindering the development of sodium ion batteries.
Based on this, Dr. Liang Chen, the Power Lithium Battery Engineering Laboratory of the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, put forward a new concept of lithium-sodium mixed ion electrolyte for the first time to build a new type of water ion battery. One type of this battery uses a compound that selectively inserts / deintercalates lithium ions as the active material, while the other electrode selects a compound that has selective intercalation / deintercalation activity for sodium ions as the active material, while mixing Li / Na. An ionic aqueous solution is used as the electrolyte.
Different from the traditional lithium-ion battery rocking chair type working principle, during the charge and discharge process of this new type of battery, lithium ions and sodium ions are inserted and desorbed only on one pole of the battery. Thanks to its unique working principle, these batteries not only store electrical energy, but also have the ability to separate lithium and sodium ions. The battery can enrich lithium ions and sodium ions through repeated charging and discharging processes. Compared with other existing chemical separation technologies, this operation is simpler and more environmentally friendly.
This new battery type not only widens the application range of the existing lithium-ion battery materials, but also opens a new way for the development of sodium-ion batteries. It has important scientific significance for enriching the energy storage battery system. In addition, the new battery's unique way of working also allows it to have Li / Na separation. Compared with the existing chemical separation technology, the technical operation of the project is simpler and more environmentally friendly, so it has an important application prospect in the large-scale separation of Li and Na in sea (or brine) water.