What is a lithium-ion battery?

Lithium-ion battery is a kind of battery using lithium metal or lithium alloy as cathode, and solution of non-aqueous electrolyte. Due to the chemical character of lithium metal is very lively, it asks high demands to the environment of processing, storage and using. So, the lithium-ion battery has not been used for a long time. With the development of science and technology, the lithium-ion battery has now become the mainstream.

Lithium battery can be roughly divided into two categories: lithium metal battery and lithium-ion battery. Lithium-ion battery does not contain metallic lithium, and can be recharged.

Is short for lithium ion batteries, lithium-ion batteries as a new type at present Energy storage battery, is gradually replacing the traditional lead-acid batteries.

Lithium ion batteries by SONY of Japan in 1990 the first successful development. It is to put the lithium ions embedded carbon (petroleum coke and graphite) formed in the cathode (traditional lithium-ion batteries use lithium or lithium alloy as negative). The anode materials commonly used LixCoO2, also use LixNiO2 and LixMnO4, electrolyte with LiPF6 + ethylene carbonate (EC) + dimethyl carbonate (DMC).

2, petroleum coke and graphite as the cathode materials, non-toxic, and abundant resources, lithium ion embedded carbon, overcome the lithium of highly active, solve the security problems of the traditional lithium battery, the positive LixCoO2 on charge and discharge performance and life span could reach a higher level, make the cost reduction, increased for the comprehensive performance of lithium ion batteries. Lithium ion battery of the 21st century will be a big market.

3, lithium ion secondary battery charge and discharge equation for LiCoO2+C=Li1-xCoO2+LixC

Second, lithium-ion battery is easily confused with the following two kinds of battery:

(1): lithium-ion batteries for lithium metal anode.

(2) lithium ion battery: using nonaqueous organic liquid electrolyte.

(3) lithium ion Polymer battery: by polymer gel liquid organic solvent, or directly with solid-state electrolyte. Lithium ion batteries with graphite cathode carbon materials commonly.

Lithium ion battery: a secondary battery (rechargeable batteries), it is mainly relying on lithium ions move between the positive and negative to work. In the process of charging and discharging, Li + embedded back and forth between the two electrodes and embedded off: when charging, Li + embedded from the anode, after anode, electrolyte embedded in the cathode in the rich lithium state; Discharge is the opposite.

Lithium batteries are divided into lithium battery and lithium ion batteries. Mobile phones and laptops are lithium ion battery, usually people commonly known as its for-lithium battery. Materials containing lithium batteries are used as the electrode, is the representative of modern high-performance batteries. But the real lithium battery, because of the large risk rarely applied in the daily electronic products.

Lithium ion batteries by SONY of Japan in 1990 the first successful development. It is to put the lithium ions embedded carbon (petroleum coke and graphite) formed in the cathode (traditional lithium-ion batteries use lithium or lithium alloy as negative). The anode materials commonly used LixCoO2, also use LixNiO2 and LixMnO4, electrolyte with LiPF6 + ethylene carbonate (EC) + dimethyl carbonate (DMC).

Petroleum coke and graphite as the cathode materials, non-toxic, and abundant resources, lithium ion embedded carbon, overcome the lithium of highly active, solve the security problems of the traditional lithium battery, the positive LixCoO2 on charge and discharge performance and life span could reach a higher level, make the cost reduction, increased for the comprehensive performance of lithium ion batteries. Lithium ion battery of the 21st century will be a big market.

Lithium ion secondary battery charge and discharge equation for LiCoO2+C=Li1-xCoO2+LixC[1]

"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.W hitting ham 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.

The earliest application of lithium-ion batteries in the cardiac pacemaker. Lithium battery self-discharge rate is extremely low, the advantages of discharge voltage flat, which makes the pacemaker implantation in the human body for a long-time operation without recharging the batteries. Lithium batteries tend to have higher than the nominal voltage of 3.0 v, is more suitable for integrated circuit power supply. Manganese dioxide batteries, is widely used in calculators, digital camera, a watch.

In order to develop more excellent performance of varieties, people of various materials are studied, so as to create an unprecedented product.

Sony in 1992 successfully developed lithium-ion batteries. Its practical application, make people's mobile phone, notebook, calculator carry type electronic equipment such as less weight and volume.

Lithium, atomic number 3, atomic weight of 6.941, it is the lightest of alkali metal elements. In order to improve safety and voltage, the scientists invented the graphite and cobalt acid lithium materials such as to store lithium atoms. The molecular structure of these materials, formed the nanometer level of small storage grid, can be used to store lithium atoms. In this way, even if the battery shell is broken, and oxygen to, also because of too much oxygen, into these small stores, making lithium atoms will not avoid contact with the oxygen blast.

Lithium battery core overcharge to voltage is higher than 4.2 V, will start to produce side effects. Of charging the higher the pressure, the higher the risk also follow. Lithium batteries voltage higher than 4.2 V, the anode materials within less than half the number of lithium atoms left, store usually break down at this time, let the battery capacity to produce permanent decline. If continue to charge, due to the storage of the cathode has been full of lithium atoms, subsequent anode materials of lithium metal accumulation in the surface. These lithium atoms from lithium ion to the cathode surface to grow in the direction of the dendritic crystal. The lithium metal crystal through the diaphragm paper makes is negative short circuit. Sometimes in short circuit batteries before the first explosion, this is because in the process of overcharge, electrolyte materials can produce gas cracking, such as making the battery shell or blow up pressure valve is broken, and let oxygen in and accumulation in the lithium atoms on the surface of the cathode reaction, then exploded.

Therefore, lithium batteries, be sure to set the upper limit of voltage, can simultaneously to the battery life, capacity, and security. The ideal maximum charging voltage of 4.2 Lithium batteries discharge voltage will be lower limit. When the batteries voltage below 2.4 V, part of the material will begin to be destroyed. And because the battery self-discharge, put the more the longer the voltage is low, therefore, discharge when had better not to 2.4 Lithium battery discharge from 3.0 V to 2.4 V during this period, the release of energy accounted for only about 3% of the battery capacity. Therefore, is an ideal discharge cut-off voltage of 3.0 V. Charge and discharge, in addition to the limit of voltage and current limits can also be necessary. When the current is too large, lithium ions to enter the store, would gather in the material surface.

After these lithium-ion get electrons, it can produce crystallization of lithium atoms in the material surface, which is same as overcharge and causes risk. Once the battery shell is broken, it would explode. Therefore, the protection of lithium-ion batteries shall include at least: upper limit of charging voltage, lower limit of discharge voltage, and upper limit of current. Generally speaking, there is a piece of protection board in a lithium-ion battery pack, besides the battery core, the board is mainly to protect all the three parts. However, it is obviously not enough. Lithium-ion battery explosion happens frequently around the world. To ensure the safety of the battery system, a more careful analysis of explosion reason must be done.

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