The negative electrode of a lithium battery is made by mixing a negative electrode active material carbon material or a non-carbon material, a binder and an additive, and pasting the paste on both sides of a copper foil, and drying and rolling. The key to the success of the lithium battery is whether it can prepare a negative electrode material that reversibly removes / intercalates lithium ions.
What are the types of lithium battery anode materials?
The first is a carbon anode material: the anode materials currently used in lithium batteries are basically carbon materials, such as artificial graphite, natural graphite, mesocarbon microspheres, petroleum coke, carbon fiber, pyrolytic resin carbon, and so on.
The second is a tin-based anode material: tin-based anode materials can be divided into two kinds of tin oxides and tin-based composite oxides. The oxides are oxides of various valence states of tin. There are currently no commercial products.
The third is a lithium-containing transition metal nitride anode material, and there are currently no commercial products.
The fourth is alloy-based anode materials: including tin-based alloys, silicon-based alloys, germanium-based alloys, aluminum-based alloys, antimony-based alloys, magnesium-based alloys, and other alloys. There are currently no commercial products.
The fifth is nano-scale anode materials: carbon nanotubes and nano-alloy materials.
What are the characteristics of lithium battery anode materials?
Graphene is a two-dimensional crystal composed of carbon atoms with only one layer of atomic thickness. It is widely praised by scientists for its thin texture, high hardness, and fast electron movement speed. It is also known as the king of new materials. Although the king's excellent chemical properties are favored by the new energy market, he still stays in the conceptual stage so far. If graphene is used as a negative electrode material for lithium batteries, it requires independent upstream and downstream industrial chains, expensive prices, and complicated processes, which makes many anode material manufacturers prohibitive.
At present, the negative electrode materials are mainly composed of natural graphite and artificial graphite, each of which has advantages and disadvantages. Natural graphite has a higher gram capacity, simple process, and cheap price, but its liquid absorption and circulation performance are worse; artificial graphite has a more complicated and expensive process, but has better circulation and safety performance. Through various technical improvements, these two graphite anode materials can be used to avoid strengths and weaknesses, but for now, artificial graphite has certain advantages in power lithium batteries.
3.Mesophase carbon microspheres
Mesophase carbon microspheres have a highly ordered layered structure, which is a typical soft carbon with a high degree of graphitization, stable structure, and excellent electrochemical performance. Mesophase carbon microspheres have higher rate performance than natural graphite and artificial graphite, and have obvious advantages for use in aeromodelling and power tools. In addition, its thermal stability and chemical stability determine that it is not prone to chemical reactions, and the use of lithium batteries increases safety assurance.
4.Silicon carbon composite material
By adding 10% silicon-based materials to artificial graphite, Tesla has achieved a battery capacity of more than 550mAh / g and a battery energy density of 300wh / kg. Now, this way of using silicon-carbon composite materials to increase the energy density of lithium batteries is one of the industry's recognized directions....