The negative electrode material used as a lithium-ion battery should satisfy the following requirements: A, embedded, de-depletion potential is low and smooth: B, embedded, deod lithium capacity; C, the non-reversible capacity of the first cycle process; D, electrochemical cycle performance is good E, the size and mechanical stability during the lithium process; F, stabilized in the electrolyte solution; G, easy to prepare, low cost; H, no environmental pollution. It is used as a wide variety of negative electrode materials for lithium ion batteries. The chemical composition according to the main body can be divided into inorganic non-metallic materials, metal materials, metal, non-metallic composite, metal oxides, and other materials. Since the graphite carbon material is a universal negative electrode material of the current commercial lithium ion battery, the graphite carbon negative material is mainly introduced.Inorganic non-metallic negative electrode materials are used as a lithium-ion battery negative electrode material primarily a carbon material, a silicon material, and other different non-metallic composites.
Carbon materials mainly include graphite carbon materials and non-graphitized carbon materials. Graphite carbon materials include natural graphite, intermediate I graphite microspheres and carbon fibers. These materials have a typical graphite layer structure, which is a common electrode material commonly used in lithium ion batteries.
Structurally, natural graphite or artificial graphite has a typical layered structure. The ideal graphite-level spacing is approximately 0.3354 nm, and adjacent atomic spacings of the carbon six-membered ring is 0. 1415 nm, and the stack sequence, graphite in accordance with the graphite layer. There are two common microprophy structures, one is a torrential ((3R) cell, a R3M space group, which is formed at a level ((3R) cell, and the other, the other is the six-party crystal formed in the ABABAB order (ZH). ), A P63 / MMC space group.
Since the radius of the lithium ion is 0.078 nm, it is much smaller than the level spacing of the graphite microplate, and therefore, the lithium ion can be embedded between the graphite layer, distributed in the six-membered ring of the carbon atom; can also be discharged Lithium ions, due to the maximum theoretical embedding state of lithium ions in graphite, lithium ion distribution in all non-adjacent six-membered rings, Li and C have a chemical metric ratio of 1: 6, and therefore, the theoretical capacity of graphite negatives C = 372.22 mA. H / g.
The graphite negative electrode material is a negative electrode material commonly used in commercial lithium ion batteries. Not only the crystallinity and microscopic structure affects the electrochemical properties of the graphite material as the negative electrode material of the lithium-ion battery, but the composition of the electrolyte is also largely influencing its inconite lithium capacity, life and magnification charge and discharge performance, but therefore. The focus of graphite negative electrode materials mainly include: the mechanism and inhibitory method of irreversible capacity loss, the relationship between graphite structure and electrochemical properties and optimization of the electrolyte system.
Silicon has a super high theoretical lithium capacity of 4200 mA ¡¤ h / g, which is an aimed material for developing prospects. However, the first non-reversible capacity of single textile silicon is particularly high, and the cycle performance is poor. Carbon can be combined with silicon to form a stable C-Si composite material, and the negative electrode material has the advantage of high capacity, stability and safety, etc., two points for the preparation of excellent C-Si composites: One is silicon needs uniform The ground is distributed in the carbon-based body; the second is that the content of silicon is moderate, and the research work in this regard is progressing Recommend: LiFePO4 Battery Manufacturer Energy storage battery Manufacturer Integrated machine energy storage battery series Manufacturer Lead lithium battery Manufacturer Outdoor Backup Battery Manufacturer Portable outdoor power supply Manufacturer Power battery Manufacturer Powerwall LiFePO4 Battery Manufacturer Battery rack Manufacturers Telecom LiFePO4 Battery Manufacturer Wall mounted battery storage Manufacturer China Lifepo4 Battery
