Button cell introduction
Button cell, refers to a battery whose overall size is like a small button. Generally speaking, it has a large diameter and thin thickness. Button batteries are classified according to their appearance. The same corresponding batteries include cylindrical batteries, square batteries and special-shaped batteries. Generally speaking, there are two kinds of button batteries: rechargeable and non rechargeable.
Common button batteries include Ag3, ag10 and AG13 batteries for toys and gifts, batteries on computer motherboard, model CR2032, cr2025 in electronic dictionary, cr2016 or sr44, sr626 on electronic watch, etc.
The English letters in front of the model name of Button cell indicate the type of battery, the numbers indicate the size, the first two digits indicate the diameter and the last two digits indicate the thickness.
Button cell classification
(1) Lithium battery
The common disposable lithium battery is lithium manganese battery with a nominal voltage of 3 V.
The new numbering method of IEC usually use for the size numbering of lithium battery. The first two digits are diameter.The last two digits are thickness, and the close number of the two is taken. For example, the approximate size of CR2032 is 20 mm in diameter and 3.2 mm in thickness.
(2) Silver oxide
The Button cell has the characteristics of long service life and large capacity. It is widely to use and has the largest application. The battery uses silver oxide as the positive electrode, metal zinc powder as the negative electrode. The electrolyte is potassium hydroxide or sodium hydroxide.
(3) Silver peroxide
The structure of the battery is basically the same as that of the silver oxide Button cell. The main difference is the anode of the battery make of silver peroxide.
(4) Alkaline manganese
The battery has large capacity, excellent low-temperature performance, cheap materials and low price. Can meet the requirements of continuous discharge with large current demand. The disadvantage is that the energy density is not enough and the discharge voltage is not stable enough. The positive pole of alkaline manganese Button cell is manganese dioxide. The negative pole is zinc, and the electrolyte is potassium hydroxide. Its nominal voltage is 1.5V.
(5) Mercury
Also known as mercury battery, it has the characteristics of high temperature, long-term storage, stable discharge voltage and good mechanical performance. But its low temperature characteristics are not good. The positive electrode of the battery is mercury and the negative electrode is zinc. The electrolyte can be potassium hydroxide or sodium hydroxide. Its nominal voltage is 1.35v.
(6) Lithium ion
The nominal voltage of lithium manganese disposable Button cell is 3V, the termination voltage is 2V, and the typical working current is 0.1-0.2ma. It uses manganese dioxide with very stable chemical properties as the cathode material and lithium metal with very high specific energy as the cathode material. The annual average capacity is reduced by no more than 2% and the storage life is long. The battery adopts semi sealed structure, which is safe to use. Lithium manganese disposable Button cell has a wide temperature adaptation range and can work normally under the conditions of – 20 to + 60 ℃. It is mostly used in electronic dictionaries, motherboards, CMOS batteries, watches and so on.
(7) Secondary lithium
It is a secondary Button cell and can charge and discharge for many times.
(8) Hammer button
The battery has the characteristics of high energy density, good storage performance, low self discharge and long service life. The disadvantage is that the internal resistance of the battery is large. The positive electrode of the battery make of manganese dioxide or iron disulfide. The negative electrode is a hammer, and the electrolyte is organic matter. The nominal voltage of Li / MnO hammer battery is 2.8V and that of Li (CF) n hammer battery is 3V.
(9) Solder pin battery
Battery with pins。 Generally, button batteries are use for small electronics, digital products, medical devices, etc. as storage power supply need to weld on the circuit board (PCBA). The battery sheet of the battery is stainless steel with nickel plating: the steel strip has hardness and is not easy to bend.
Button cell precautions
Button batteries are not within the mercury-free ban of ordinary dry batteries, and a small amount of mercury is still allowed. Must be recycled in accordance with the instructions of the environmental protection unit