Definition and classification of cylindrical lithium-ion batteries

1. What is a cylindrical lithium battery?

1. The definition of cylindrical battery
Cylindric lithium battery is divided into lithium iron phosphate, lithium cobalt acid, lithium manganese acid, cobalt manganese mixed, ternary material system, shell is divided into steel shell and polymer two kinds, different materials system battery has different advantages. At present, the cylinder is mainly made of steel shell cylindrical lithium iron phosphate battery. The performance of this battery is high capacity, high output voltage, good charge-discharge cycle performance, stable output voltage, large current discharge, stable electrochemical performance, safe use, wide operating temperature range, friendly to the environment. Widely used in solar lamps, lawn lamps, backup energy, power tools, toy models.

2. Cylindrical battery structure
A typical cylindrical battery structure includes: housing, cap, positive electrode, negative electrode, diaphragm, electrolyte, PTC element, gasket, safety valve, etc. The general battery shell is the negative electrode of the battery, the cap is the positive electrode of the battery, and the battery shell is made of nickel-plated steel plate.

3, the advantages of cylindrical lithium battery
Compared with the soft pack and the square lithium battery, the cylindrical lithium battery has the longest development time, higher standardization degree, more mature technology, high yield and low cost.
· Mature production technology, low PACK cost, high yield rate of battery products and good heat dissipation performance
· Cylindrical battery has formed a series of international unified standard specifications and models, mature technology, suitable for mass continuous production.
· The specific surface area of the cylinder is large and the heat dissipation effect is good.
· Cylindrical batteries are usually sealed batteries, so there is no maintenance problem during use.
· The battery shell has high pressure resistance, and there will be no phenomena such as expansion of square and flexible packaging batteries during the use process.

4. Cylindrical battery cathode material
At present, the mainstream commercial cylindrical battery cathode materials mainly include lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), ternary (NMC), lithium iron phosphate (LiFePO4), etc. Different material system batteries have different characteristics, and the comparison is as follows:

5, cylindrical battery anode material
Cylindrical battery anode materials can be roughly divided into six kinds: carbon anode materials, alloy anode materials, tin-based anode materials, lithium transition metal nitride anode materials, nanoscale materials, nano anode materials.
· Carbon nanoscale material anode materials: At present, the anode materials that have been actually used in lithium ion batteries are basically carbon materials, such as artificial graphite, natural graphite, mesophase carbon microspheres, petroleum coke, carbon fiber, pyrolytic resin carbon, etc.
· Alloy anode materials: including tin base alloy, silicon base alloy, germanium base alloy, aluminum base alloy, antimony base alloy, magnesium base alloy and other alloys. There are no commercial products at present.
· Tin-based anode materials: Tin-based anode materials can be divided into tin oxide and tin based composite oxide two kinds. Oxides refer to the oxides of various valence states of metal tin. There is currently no commercial product.
· Lithium-containing transition metal nitride anode material, currently there is no commercial product.
· Nano-scale materials: carbon nanotubes and nano-alloy materials.
· Nano-anode materials: Nano-oxide materials