a lithium ion battery is a secondary battery (rechargeable battery), which mainly depends on moving lithium ions between the positive electrode and the negative work. In the charge-discharge process, Li + and from between the two electrodes of intercalating and deintercalating: charging, Li + deintercalated from the positive electrode, a negative electrode through the electrolyte is embedded, the negative electrode is a lithium-rich state; the opposite discharge.
1. Introduction lithium ion battery
Lithium and lithium-based batteries into lithium ion batteries. Mobile phones and laptops use lithium-ion batteries are usually people commonly known as a lithium battery. Batteries generally use lithium-containing material as the electrode elements, it is representative of the modern high-performance batteries. The real lithium batteries due to the risk of large, rarely used in everyday electronic products.
by a lithium ion battery Sony Corporation of Japan in 1990, the first successful development. It is the lithium ions on carbon (graphite and petroleum coke) to form a negative electrode (lithium conventional lithium or lithium alloy as a negative electrode). The positive electrode material used LixCoO2, also used LixNiO2, and LixMnO4, electrolyte solution LiPF6 + diethylene carbonate (EC) + dimethyl carbonate (DMC).
petroleum coke and graphite as the negative electrode material non-toxic, and sufficient resources, carbon lithium ions, to overcome the high activity of lithium, solve the security problems of the conventional lithium batteries, the positive electrode are LixCoO2 on charge and discharge performance and life It can reach a higher level, so that cost reduction, in short, the overall performance of the lithium ion battery can be improved. Lithium-ion batteries is expected in the 21st century will be a large market.
A lithium ion secondary battery is charged, the reaction formula during discharge was LiCoO2 + C = Li1-xCoO2 + LixC
2. Distinction lithium ion battery
The following lithium-ion battery with two easily battery types confusion:
(1) lithium battery: metallic lithium as the negative electrode.
(2) Lithium-ion battery: a non-aqueous liquid organic electrolyte.
(3) The lithium ion polymer batteries: liquid gelled with a polymer to an organic solvent or directly with whole solid electrolyte. Lithium ion batteries generally graphite-based carbon material negative electrode.
3. the development of a lithium ion battery
In 1970, Exxon M.S.Whittingham titanium disulfide as a positive electrode material, a lithium metal as a negative electrode material, a first lithium battery. Lithium battery cathode material is manganese dioxide or thionyl chloride, lithium anode. After assembly, i.e. the battery voltage is completed, no charge. Lithium-ion batteries (Li-ion Batteries) Lithium is evolved. For example, before the cameras in a coin cell lithium battery belongs. This battery can be charged, but poor cycle performance, easy to form crystals of lithium during the charging and discharging cycle, resulting in internal short circuit of the battery, so that under normal circumstances the battery charging is prohibited. R.R.Agarwal
1982 years Illinois Institute of Technology (the Illinois Institute of Technology), and found that lithium ions has a characteristic J.R.Selman embedded graphite, this process is rapid and reversible. Meanwhile, a lithium battery using metal lithium is made, which concern security risks, so people try to use the graphite intercalation of lithium ions characteristic of making a rechargeable battery. The first lithium-ion graphite electrode trial available by the success of Bell Labs.
In 1983 M.Thackeray, J.Goodenough et al found that manganese spinel cathode material is excellent in having a low, stable and good electrical conductivity, the lithium conductivity performance. Its decomposition temperature is high, and much lower than the lithium oxide, cobalt oxide, even if the short circuit, overcharging, it is possible to avoid the burning, the risk of explosion.
In 1989, A.Manthiram J.Goodenough and found positive using anionic polymerization will produce a higher voltage.
In 1992 Sony Corporation invention is a carbon material in the negative electrode to the positive electrode containing a lithium compound as a lithium battery, the charging and discharging process, without the presence of lithium metal, lithium ions only, which is a lithium ion battery. Subsequently, the lithium-ion batteries revolutionized the face of consumer electronics products. In such a lithium cobaltate positive electrode material of a battery, the main power supply of portable electronic devices.
In 1996 Padhi and Goodenough found phosphate having an olivine structure such as iron lithium phosphate (and LiFePO4), than conventional positive electrode material more secure, in particular, high temperature resistance, overcharging performance far more than a conventional lithium ion battery materials.
Throughout the history of the development of the battery, the current can be seen that three battery characteristics of industrial development in the world, one is the rapid development of green battery, including a lithium ion battery, a nickel hydrogen battery or the like; Second primary battery to the battery conversion, which in line with the sustainable development strategy; third is to further the battery is small, light, thin direction. In a rechargeable cell, the highest specific energy of the lithium ion battery commercially available, in particular a polymer lithium ion batteries, rechargeable batteries can be realized a thinner shape. Because the volume of the lithium ion battery is higher than the ratio of mass and energy energy, non-polluting and can be charged, comprising three major characteristics of the current development of industrial batteries, so there is rapid growth in the developed countries. Telecommunications, information market development, particularly in mobile phones and laptops extensive use, the lithium-ion battery to bring market opportunities. The lithium-ion battery polymer lithium ion battery safety its unique advantages, will gradually replace the liquid electrolyte lithium ion batteries, and lithium ion battery has become the mainstream. Polymer lithium-ion battery known as the “21st century battery”, a new era will open up prospects for the development of the battery is very optimistic.
in March 2015, Professor Sharp and Koki Tanaka of Kyoto University in Japan together successfully developed a life of up to 70 years of lithium-ion batteries. The trial of the lithium ion battery longevity, 8 cm3 volume, charge and discharge times of up to 2.5 million times. And Sharp side said, this lithium ion battery longevity actual discharge after 10,000, its performance is still stable.
4. The lithium ion battery part
steel / aluminum / cylindrical / flexible packaging:
(1) positive electrode – active material is typically lithium manganate or lithium cobalt oxide, lithium nickel-cobalt-manganese oxide material, electric bicycles are generally used nickel cobalt manganese lithium (commonly known three yuan) or three yuan + a small amount of lithium manganate, lithium manganate and pure lithium iron phosphate is due to the large volume, high-cost performance is not good, or phased out. Fluid conducting electrode using an electrolytic copper foil of thickness 10 – 20 microns.
(2) separator – one kind of a special polymer film was formed, the film has a microporous structure that allows free passage of lithium ions and electrons can not pass through.
(3) the anode – active material, an electrolytic copper foil of a thickness of 7-15 microns carbon, conductive graphite collector, graphite or similar structure.
(4) The organic electrolyte – carbonate-based solvent dissolving lithium hexafluoro phosphate, polymer gel electrolyte is used.
(5) the battery case – into steel (square rarely used), aluminum, nickel-plated steel (cylindrical battery), plastic film (flexible) or the like, as well as cell blocks, but also battery positive and negative terminations.