First, the name of lithium-ion batteries Brief Introduction
We are now widely used lithium-ion battery is a lithium battery evolved. Therefore, understanding the lithium-ion batteries, we first to introduce lithium battery.
For example, before the cameras used in lithium battery button cell belongs to. Lithium battery is a lithium metal anode material, cathode material is carbon material. Named in accordance with customary law of us, we call this the battery is lithium batteries.
Lithium-ion battery is a lithium cobalt oxide cathode material, anode material is carbon material. Batteries produced by cathode carbon anode materials of lithium ion in and move out in the realization of the embedded battery charge and discharge process, in order to distinguish it from traditional lithium batteries, so people called lithium-ion batteries.
Second, the extensive use of lithium-ion batteries
The purpose is to develop high technology to better serve humanity. Lithium-ion batteries since its inception in 1990, because of its superior performance has been rapid development and is widely used in society. Lithium-ion battery to other batteries by the incomparable advantage of the rapid occupation of a number of areas, like the well-known mobile phones, notebook computers, small video camera and so on, more and more countries and the battery used in military applications. Application shows that the lithium-ion battery is an ideal for small green power.
Third, the main components of lithium-ion battery
(1) battery cover
(2) is very ---- lithium cobalt oxide active material is
(3) divide a special kind of composite film ----
(4) The negative pole active material is carbon ----
(5) Organic electrolyte
(6) Battery housing
Fourth, the superiority of lithium-ion battery
We often say that the advantages of lithium-ion battery is for the traditional nickel-cadmium batteries (Ni / Cd) and nickel-metal hydride battery (Ni / MH) in terms of. So, what was good lithium-ion batteries it?
(1) high voltage
(2) than the energy of large
(3) Long cycle life
(4) low self-discharge
(5) No memory effect
The following is a nickel-cadmium, nickel hydrogen, lithium-ion battery performance comparison:
Technical parameters of nickel cadmium batteries Ni-MH battery lithium-ion battery
Operating Voltage (V) 1.2 1.2 3.6
Weight specific energy (Wh / Kg) 50 65 105-140
Volume specific energy (Wh / l) 150 200 300
Discharge life (times) 5005001000
Self-discharge rate (% / month) 25-3030-356-9
Whether the memory effect with or without
Whether there is pollution-free
(Note: The charging rates are 1C)
Fifth, the working principle of lithium-ion battery
We all know, the lithium-ion battery is a lithium cobalt oxide cathode material, anode is carbon.
The working principle of lithium-ion battery is that its charging and discharging. When charging the battery, the battery on the positive ion generation, generation of lithium-ion movement through the electrolyte to the cathode. As the carbon cathode layered structure, it has many pores, to reach the negative electrode of lithium-ion embedded in porous carbon layer, the more embedded lithium-ion, the higher the charge capacity.
Similarly, when the discharge of the battery (ie, the process we use the battery), embedded in the negative ion of carbon layer prolapse, and movement back to positive. Back to the cathode of lithium-ion more discharge capacity is higher. We usually refer to the battery capacity refers to the discharge capacity.
It is obvious that in the lithium-ion battery charge and discharge process, lithium ions in the positive → negative → positive from the state of motion. If we liken the lithium-ion battery for the rocking chair, rocking chair for the battery terminals at both ends, while the lithium-ion as excellent athlete, running back and forth in a rocking chair at both ends. Therefore, the experts gave the lithium-ion battery the name of a lovely rocking chair batteries.
Six, the assembly process of lithium-ion battery
Lithium-ion battery technology is very strict, complex, here only a brief one of the main process.
Solvent and with a special adhesive and powder form, respectively, positive and negative active material mixture, the high-speed mixing evenly, the positive and negative materials made of paste.
Slurry will be made of metal foil coated evenly on the surface, drying, respectively, into positive and negative pole piece.
By the positive electrode - diaphragm - negative film - put away the order from top to bottom diaphragm, coiled into the battery very core, and then the injection of the electrolyte, sealing and other process, to complete the battery assembly process, the system into a finished battery.
With a dedicated battery charging and discharging equipment, battery charging and discharging of the finished product testing, only the batteries are tested for each screening battery of qualified products, to be manufactured.
Seven security features lithium-ion battery
Lithium-ion batteries has been very widely used in people's daily lives, so it definitely should be the safety performance of the first lithium-ion battery assessment indicators. For the lithium-ion battery safety performance assessment indicators, provides a very stringent international standards, a qualified safety of lithium-ion battery performance should meet the following conditions.
(1) short: no fire, no explosion
(2) Overcharge: No fire, no explosion
(3) hot box test: no fire, no explosion (150 ℃ temperature 10min)
(4) puncture: do not explode (with Ф3mm nail through the battery)
(5) plate impact: No fire, no explosion (10kg weight from the high pound battery 1M)
(6) burning: do not explode (gas flame is battery)
VIII, lithium-ion battery safety features is how to achieve it?
In order to ensure safe and reliable lithium-ion batteries used, the experts had a very strict, careful design of battery safety, safety assessment in order to achieve the battery indicator.
(1) divide 135 ℃ Automatic shutdown protection
Adopts the international advanced Celgard2300PE-PP-PE three-layer composite film. The battery temperature reaches 120 ℃ circumstances, both sides of the PE film composite membrane hole closed, the battery internal resistance increases, the battery internal temperature slowed down when the battery temperature reaches 135 ℃, PP membrane hole closed, the battery within the circuit, the battery is no longer temperature, to ensure safe and reliable battery.
(2) adding additives to the electro-hydraulic
In the battery charging, the battery voltage is above 4.2v conditions, the electro-hydraulic additives and other substances in the polymer electro-hydraulic, battery internal resistance mate increases the formation of large-scale circuit inside the battery, the battery is no longer warming.
(3) The composite battery cover
Explosion-proof structure of the battery cover by notch, the battery temperature, the cell activation process inside the part generated by gas expansion, the battery internal pressure increased, the pressure reaches a certain level of notch rupture, gas discharge.
(4) test a variety of environmental abuse
For the misuse of tests, such as external short circuit, overcharge, acupuncture, plate impact, burning, etc., examine the safety performance of the battery. At the same time the battery temperature shock test and vibration, drop, impact and other mechanical properties investigated battery performance under actual use conditions.
September, lithium-ion battery is a new green battery
"Care for the environment, protection of the Earth" is the bounden duty of every one of us. How do our environmental philosophy reflected in the action it?
As the battery consumers should purchase and use of new green battery; as a battery manufacturer, should produce new green battery. Only through our concerted efforts to create, protect our beautiful and harmonious natural environment.
New green battery is put into use in recent years have been developed or are in a class of high-performance, non-polluting batteries. Now widely used lithium-ion batteries, nickel metal hydride batteries and are promoting the use of mercury-free alkaline manganese batteries, and is developed lithium or lithium ion plastic batteries, fuel cells, electrochemical energy storage capacitors are all new super- green areas of the battery. In addition, the use of solar energy has been widely used for photoelectric conversion of solar cells (also known as photovoltaic power generation), also fall into this category.