What is the current status of lithium battery technology?

The performance of high-voltage lithium batteries depends importantly on the structure and properties of active materials and electrolytes. The cathode material is the most critical core material, and the matching effect of the electrolyte is also very important. At present, the most widely researched and applied high-voltage cathode material is lithium cobalt oxide with a two-dimensional layered structure. The structure is α-NaFeO2 type, which is more suitable for intercalation and removal of lithium ions. The theoretical energy density of lithium cobalt oxide is 274mAh/g, the processing technology is simple, the electrochemical performance is stable, and the market share is high. The actual energy density of lithium cobalt oxide is about 167mAh/g (working voltage is 4.35V). Increasing its working voltage can significantly increase its energy density. For example, increasing its operating voltage from 4.2V to 4.35V can increase its energy density by about 16%. However, under Gaodianya, lithium ions are intercalated and degraded from the material many times, causing the structure of lithium cobalt acid to change from a tripartite system to a monoclinic system. At this time, the lithium cobalt oxide material no longer has the ability to insert and deactivate lithium ions, and at the same time, the particles of the positive substance become loose and fall off from the set fluid, resulting in an increase in the internal resistance of the battery and poor electrochemical performance. At present, the modification of lithium cobalt oxide cathode materials is important to improve the crystal structure stability and interface stability of the material from the aspects of doping and coating. Lithium cobalt oxide high voltage materials have been used in high energy density batteries. For example, manufacturers of high-end mobile phone battery put forward higher requirements for the performance of batteries, which importantly reflects higher requirements for energy density. For example, the energy density of a 4.35V mobile phone battery with carbon as the negative electrode is about 660Wh/L, and the energy density of a 4.4V mobile phone battery is about 740Wh/L, which requires a positive electrode material. Higher compaction density, higher space utilization, high and high pressure material structure has better stability. However, lithium cobalt oxide electrode materials have shortcomings such as lack of cobalt resources and high prices. In addition, cobalt ion has certain toxicity, which limits its wide application in power lithium ion batteries. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: How to choose a button battery box?