Working principles of lithium-ion battery and its assembly process

Everyone has already known that, the anode materials of lithium ion battery are lithium cobalt oxide, and cathode is carbon.

The working principle of lithium-ion battery refers to its charge and discharge principle. When charging the battery, lithium ions is generated in the anode, the generated lithium ions move to cathode through the electrolyte. As a cathode, the carbon is in layer structure, it has many pores, lithium ions arrive at cathode and is embedded into the microporous carbon layer, the more lithium ions embedded, the more the charging capacity has.

Likewise, when to discharge the battery (i.e., we use the battery process), embedded in the cathode carbon layer of emergence, lithium ions and movement back to the anode. Back to the anode of lithium ion, the more the higher the discharge capacity. We usually mean by battery capacity is the discharge capacity.

It is not hard to see, in the process of charging and discharging lithium ion batteries, lithium ion in the motion state from the positive and negative to the anode. If we compared the image of the lithium ion battery as a rocking chair, rocking chair at both ends of the poles for the battery, and lithium ion as excellent athlete, running to and for in the ends of the rocking chair. So, the experts gave lithium ion battery rocking-chair batteries a cute name.

Assembly:

Anode piece - according to the positive plate, diaphragm, diaphragm top-down order, made by winding the battery core, then through injecting electrolyte, such as sealing process, namely the complete battery assembly process, to make battery products.

Formation

With dedicated to charge and discharge test of battery products, battery charging and discharging equipment of each battery only for testing, select qualified battery products, to the factory.

Lithium ion batteries with carbon as negative material, with lithium compounds as positive, no metal lithium exists, only the lithium ions. Lithium ion battery refers to the floorboard of the lithium ion embedded compounds as the anode material battery. Lithium ion battery charge and discharge process, is the embedded lithium ion and embedded process. Embedded in lithium ion and embedded process, at the same time with lithium ion equivalent embedded electronic and embedded off (habit to use embedded or embedded said, on the positive and negative) inserted with insert or take off., in the process of charging and discharging lithium ion in the back and forth between positive and negative electrode embedded/embedded and insert/take off the plug, vividly called "rocking-chair batteries".

Lithium ion battery has a large energy density, the average output voltage. Small self-discharge, below 10% per month. No memory effects. Wide working temperature range for - 20 ℃ ~ 60 ℃. Loop performance is superior, can fast charge and discharge, charging efficiency is as high as 100%, and the output power. Long service life. No environmental pollution, known as the green cells.

Working principle

Lithium ion batteries with carbon as negative material, with lithium compounds as positive, no metal lithium exists, only lithium ion, this is the lithium ion battery. Lithium ion battery refers to the floorboard of the lithium ion embedded compounds as the anode material battery. Lithium ion battery charge and discharge process, is the embedded lithium ion and embedded process. Embedded in lithium ion and embedded process, at the same time with lithium ion equivalent embedded electronic and embedded off (habit to use embedded or embedded said, on the positive and negative) inserted with insert or take off., in the process of charging and discharging lithium ion in the back and forth between positive and negative electrode embedded/embedded and insert/take off the plug, vividly called "rocking-chair batteries".

When charging the battery, the battery has lithium ions generated in the anode, the generated lithium ions through the electrolyte to the negative movement. As a cathode carbon layer structure, it has many pores, reach the cathode of lithium ion is embedded into the microporous carbon layer, the embedded lithium ion, the more the higher the charge capacity. Also, when to discharge the battery (i.e., we use the battery process), embedded in the cathode carbon layer of emergence, lithium ions and movement back to the anode. Back to the anode of lithium ion, the more the higher the discharge capacity.

General the lithium battery Charging current is set in between 0.2 C and 1 C, the greater the current, the faster the charging, also the bigger the battery heating. Moreover, large current charging, capacity is not full, because inside the battery electrochemistry reaction takes time. Just like beer, fall too fast will produce bubbles, instead.

Precautions for use

For the battery, normal use is the process of discharge. Lithium electricity Pool discharge to note:

First, the discharge current can't too much, too much current lead to internal batteries, may cause permanent damage. On the phone, this is no problem, cannot consider.

As can be seen from the right, the bigger the battery discharge current, the smaller the discharge capacity, voltage drop quickly.

Second, absolutely can't discharge. Lithium battery internal storage electric energy is a kind of reversible chemical changes by electrochemical, excessive discharge can cause irreversible change of the chemical reaction, so the most afraid of lithium-ion batteries discharge, once the discharge voltage is lower than 2.7 V, could lead to battery scrap. In mobile phone inside the battery has been installed protection circuit, didn't low to the extent of the damage to the battery voltage, protection circuit can work, stop discharge.

"Lithium battery", is a kind of lithium metal or lithium alloy anode materials, the use of water battery electrolyte solution. Lithium battery as early as 1912 by GilbertN. Lewis is put forward in this study. In the 1970 s, M.S. Whittingham and began to research on lithium ion battery are put forward. Due to the lithium chemistry is very lively, making lithium metal processing, storage, use, very high demand on the environment. So, the lithium battery has not been applied for a long time. With the development of science and technology, the lithium battery has now become the mainstream.

Lithium battery can be roughly divided into two categories: lithium battery and lithium ion batteries. Lithium ion battery does not contain lithium metal state, and can be recharged. The fifth generation of rechargeable battery product lithium battery was born in 1996, its security, specific capacity, self-discharge rate and cost performance is better than that of lithium ion batteries. Because of its high technical requirements limit, now only a few countries in the production of this kind of lithium battery.

1, in the 1970 s, M.S.W exxon hittingham using titanium sulfide as the anode material, metallic lithium as negative material, made the first lithium battery.

2, 1980, J. Goodenough discovered cobalt acid lithium can be used as lithium ion battery cathode material.

3, 1982, university of Illinois institute of technology (the Illinois Institute of Technology) R.R.A garwal and J.R.S elman found embedded lithium ion has the properties of the graphite, the process is quick, and reversible. At the same time, made of metallic lithium batteries, much attention has been paid to its safety problems, so people try to take advantage of the characteristics of lithium ion embedded graphite production of rechargeable batteries. The first available lithium-ion graphite electrode successfully trial-produced by bell LABS.

4, 1983 m. hackeray, J.G galaxite oodenough and others found to be excellent cathode material, with a low price, stable and good conductive lithium, guide performance. Its decomposition temperature is high, and oxidation is far lower than the cobalt acid lithium, even if a short circuit, over charge, also can avoid the risk of combustion and explosion.

5, 1989, arjun anthiram and J.G oodenough anionic polymerization is found that the positive will generate higher voltage.

6, 1991, SONY released the first commercial lithium-ion batteries. Subsequently, lithium ion batteries have revolutionized the face of consumer electronics products.

Padhi and Goodenough discovered 7, 1996 has olivine structure of phosphate, such as lithium iron phosphate (LiFePO4), more superiority than traditional cathode material, therefore has become the mainstream of the anode materials.

With widely use of digital products such as mobile phones, laptops and other products, lithium-ion battery is widely used in such products due to its excellent performance, and gradually applied in other area products. In 1998, Tianjin Institute of Power Supply began commercial production of lithium-ion battery. Traditionally, people called the lithium-ion battery as lithium battery, but the two batteries are not the same. Lithium-ion battery has become the mainstream.

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