Basic performance and development status of lithium battery anode materials

As a lithium-ion battery negative electrode material, it requires the following basic properties: lithium-ion battery (1) The insertion redox potential of lithium ions in the negative electrode matrix is u200bu200bas low as possible, close to the potential of metal lithium, so that the battery's output voltage is high; (2) A large amount of lithium in the matrix can be reversibly inserted and deintercalated to obtain high capacity density; (3) The oxidation-reduction potential will not change significantly, and stable charging and discharging can be maintained; (4) The intercalation compound should have better Conductivity and ionic conductivity, which can reduce polarization and enable high-current charging and discharging; (5) From a practical point of view, the main material should be cheap and pollution-free; carbon anode lithium-ion batteries are safe and cycle life Shows good performance, and carbon materials are inexpensive and non-toxic. At present, carbon anode materials are widely used in commercial lithium-ion batteries. In recent years, with the continuous in-depth research of carbon materials, it has been found that by surface modification and structural adjustment of graphite and various carbon materials, the specific capacity has been greatly increased from the original theoretical value of 372mAh/g to 700mAh/g~ 1000mAh/g, while greatly increasing the specific energy of lithium-ion batteries. At present, the important anode materials for lithium-ion batteries that have been researched and developed include graphite, petroleum coke, carbon fiber, pyrolysis carbon, mesophase pitch-based carbon microspheres (MCMB), carbon black, glass charcoal, etc., among which graphite and petroleum coke are the most important Value. Generally speaking, according to the degree of graphitization, carbon anode materials can be divided into graphite, soft carbon and hard carbon. Graphite material has good conductivity, high crystallinity, and a good layered structure. The charge and discharge capacity can reach more than 300mAh/g, and the charge and discharge efficiency is more than 90%. It can be used with lithium borate and lithium manganate, which are the cathode materials for supplying lithium sources. , Lithium nickelate, etc., the battery composed of high average output voltage, is currently the most widely used negative electrode material for lithium-ion batteries. Soft carbon materials are carbon materials that are easily graphitized, and refer to amorphous carbon that undergoes graphitization at a high temperature above 2500°C. Soft carbon has a low degree of graphitization and good compatibility with electrolyte. Common soft carbons include petroleum coke, needle coke, carbon fiber, and carbon microspheres. Hard carbon materials refer to carbon materials that are difficult to graphitize. They are formed by thermal decomposition of high molecular polymers and have a large lithium capacity (500-1000mAh/g). This type of carbon is also difficult to graphitize at high temperatures above 2500°C. Common hard carbons include resin carbon (phenolic resin, epoxy resin, and polycarbonate). Currently, the anode materials for lithium-ion batteries that have been researched and developed are mainly graphite, petroleum coke, and carbon fiber. , Pyrolysis carbon, mesophase pitch-based carbon microspheres (MCMB), carbon black, glassy carbon, etc., among which graphite and petroleum coke have the most application value. Disclaimer: Some pictures and content of articles published on this site are from the Internet, if any Please contact to delete the infringement. Previous: Detailed explanation of the principle of lithium battery repair