RECHARGEABLE COIN CELL BATTERY COMPOSITION

Daily life, our demand for button batteries is also relatively large, a variety of toys, car remote control and other electronic products will use this micro-miniature button battery, although they will be used, but many people are familiar and unfamiliar with button batteries, today I will give you a popularization.

Button battery basic introduction.

Lithium-ion button battery is mainly composed of positive shell, negative shell, (positive / negative) pole piece, diaphragm, gasket, shrapnel, electrolyte, etc..

CR2032 in the commonly used regular commodity button battery C indicates positive pole Mno2, BR series, B indicates positive pole fluorocarbon. c or B represents the buckle system, R represents the battery shape is round. The first two digits are the diameter (unit mm), and the last two digits are the thickness (unit 0.1mm), taking two close numbers. For example, the approximate size of CR2032 is 20mm in diameter and 3.2mm in thickness.

Coin cell battery composition 

1 button cell case

CR2032 button cell shell, positive shell is larger, negative shell surface mesh structure, smaller, so the general assembly process begins with the negative shell.

2 Pole piece

The preparation process of the electrode has an important impact on whether the electrochemical performance can be fully developed.

The laboratory electrode preparation process is generally divided into two processes: mixing and coating. The mixing process includes manual grinding method and mechanical slurry mixing method, and the coating process is manual coating and mechanical coating.

The mixing process is based on the amount of material supplied to determine the use of manual grinding or mechanical slurry method, the amount of slurry mixed at a time in the laboratory is limited, often using manual coating, when the slurry is sufficient to use a small coating machine. The whole production process needs to be carried out in a dry environment, the materials and equipment used need to be kept dry, so the production of batteries can not be used for a long time to store the pole piece.

3 diaphragm

The diaphragm used in the laboratory is generally Celgard 2400 or other products of the Celgard series. After stamping into small round pieces, the diameter is slightly larger than the positive and negative electrodes. Diaphragms can be selected according to the battery performance requirements.

What is the purpose of the diaphragm?

Simply put, if there is no diaphragm, the positive and negative electrodes are in direct contact, i.e. short-circuiting, which is why some button cells are inhibited from producing lithium dendritic crystals, in order to prevent them from piercing the diaphragm, causing a local short circuit and resulting in a safety accident. Diaphragm is generally used polyethylene and other polymer materials, non-conductive, its structure has many microporous, allowing lithium ions through, although it is an insulator, but does not allow electrons through the statement is not accurate.

4 lithium sheet (i.e. negative sheet)

Negative sheet diameter is slightly smaller than the diameter of the negative shell, CR2032 lithium sheet diameter of 15.8mm, the laboratory usually uses a diameter of 14mm corresponding CR2032 button cell) stamping die stamping positive sheet. It is worth noting that the lithium sheet is relatively soft and easily deformed, so before installing the battery, you can use the positive shell (because it is relatively large) to flatten the deformed lithium sheet. In addition, lithium metal is easy to oxidize and deteriorate in the air and explode easily in water, so the purchased lithium metal sheet needs to be opened in the glove box. Be careful not to damage the glove when opening.

5 Gasket

The gasket is a round aluminum sheet with the same diameter as the size of the lithium sheet. In the experiment, different specifications and thicknesses can be purchased as needed.

Note: The gasket, positive and negative shells and other components should be cleaned with alcohol repeatedly by ultrasonic before use, and then dried with a blast drying oven.

6 Shrapnel (support piece)

Shrapnel is mainly used to support the battery. Without the shrapnel, the battery will be very flat in the pressure cell step and the internal components may be crushed. The shrapnel is added to the negative side only, but if the shrapnel is added to both the positive and negative side, the buckling cannot be closed during the pressure cell step, resulting in the electrolyte coming in contact with air and the experiment failing.

7 Electrolyte.

Different materials generally correspond to different electrolytes, do not try to save trouble in the experiment, small quantities of electrolytes can be requested from the company, and will generally be given. Individual special electrolytes, such as low-temperature electrolytes, may need to be purchased, and the price is not low.

Recently, the market price of various materials has increased significantly, but it does not affect the production of our battery supply, if you need button cell, welcome to consult FUNPACK Battery Technology.