Lithium-ion battery Name Description
Is now widely used lithium-ion battery is evolved by a lithium battery. Recognize the lithium-ion battery, the first to introduce lithium battery.
For example, before the cameras used button batteries are lithium batteries. The negative electrode material for lithium battery is a lithium metal, a positive electrode material is a carbon material. In accordance with the naming rules on everyone is used to, we call this battery is a lithium battery.
The positive electrode material for lithium ion battery is a lithium cobalt oxide, a negative electrode material is a carbon material. Battery through the positive lithium ions generated at the anode carbon material embedded and move out of the battery charge and discharge process, in order to distinguish it from the traditional sense of the lithium battery known as lithium-ion battery.
Wide variety of uses of the lithium ion battery
The purpose of the development of high-tech in order to make it better serve the human. Lithium-ion batteries since its inception in 1990, because of its excellent performance has been rapid development, and widely used in society. Lithium-ion battery unparalleled advantages to other battery quickly occupied many areas, like the well-known mobile phone, laptop, small camera and more and more countries the batteries used in military applications. The application shows that the lithium-ion battery is an ideal green power.
The main constituent of the lithium-ion battery
(1) The battery cover
(2) Positive electrode - active material for lithium cobalt oxide
(3) diaphragm - a special composite membrane
(4) The negative electrode - active material is carbon
(5) an organic electrolyte solution
(6) The battery housing
Superiority of the lithium ion battery
We often say that the superiority of lithium-ion batteries in terms of conventional nickel cadmium batteries (Ni / Cd) and nickel-metal hydride battery (Ni / MH). Lithium-ion battery, then what was good?
(1) Operating voltage high
(2) energy
(3) long cycle life
(4) low self-discharge rate
(5) no memory effect
(6) pollution
The following is a nickel-cadmium, nickel metal hydride, lithium-ion battery performance comparison:
Technical parameters of nickel-cadmium batteries nickel-metal hydride battery lithium-ion battery
Operating voltage (V) 1.2 1.2 3.6
The weight ratio of energy (Wh / Kg) 50 65 105-140
The volume ratio of the energy (Wh / l) 150 200 300
Charge-discharge life (times) 500 500 1000
Self-discharge rate (% / month) 25-3030-356-9
Have memory effect there is no
Non-polluting Yes No No
(Note: The charge rate of 1C)
Lithium-ion battery works
As we all know, the positive electrode material of the lithium-ion battery is a lithium cobalt oxide, a negative electrode is a carbon.
The lithium-ion battery works is its charging and discharging. When charging the battery, the positive electrode of the battery manufacturer, lithium ions generated the generated lithium ion movement through the electrolyte to the negative electrode. And carbon as a negative electrode layered structure, it has a lot of micropores, reach the negative electrode of lithium ions embedded into the porous carbon layer, the embedded lithium ions, the more the higher the charge capacity.
Similarly, when the discharge of the battery (the process) we use the battery, the lithium-ion embedded in the carbon cathode layer prolapse movement back to the cathode. Back to the positive electrode of the lithium ion, the more the higher the discharge capacity. We usually battery capacity of said fingers is the discharge capacity.
Not difficult to see during charging and discharging of the lithium-ion batteries, lithium-ion is from the positive → negative → positive state of motion. If we liken the lithium-ion battery for a rocking chair, rocking chair at both ends of the poles of the battery, the lithium-ion like a good athlete, running back and forth at both ends of the rocking chair. Therefore, the experts gave a rocking chair battery lithium-ion battery is a cute name.
The assembling process of the lithium-ion battery
Lithium-ion battery technology is very strict and complex, there can only be a brief introduction of several major processes.
(1) Pulp
Using a special solvent and the adhesive, respectively, the positive and negative active material and the powdery mixture,
After high-speed Stir slurried positive and negative substances.
(2) The coating film
The slurry was uniformly coated surface of the metal foil, drying, respectively made positive
The negative electrode sheet.
(3) assembly
Positive films - diaphragm - negative film - Diaphragm top-down order is put away, winding
Made the battery pole core, and then injected into the electrolyte, sealing process, to complete the electrical
Pool assembly process, finished goods battery.
(4) into
Finished battery charge and discharge testing with a dedicated battery charging and discharging equipment, for each
Only battery detection, screening qualified finished battery pack to be shipped.
The security features of the lithium-ion battery
The lithium-ion battery has been very widely used in people's daily lives, so the performance of its security should be the first item of the lithium-ion battery assessment indicators. Indicators for the assessment of the safety performance of lithium-ion battery, the international regulations of very strict criteria, a qualified lithium-ion battery safety performance should meet the following criteria.
(1) Short: No fire, no explosion
(2) Overcharge: no fire, no explosion
(3) hot box test: no fire, no explosion (150 ° C constant temperature for 10 minutes)
(4) acupuncture: no explosion ( 3mm nail penetrate the battery)
(5) plate impact: no fire, no explosion (10kg heavy pound battery from 1M height)
(6) incineration: and no explosion (gas flame BBQ battery)
The lithium-ion battery safety features is how to achieve?
In order to ensure the safe and reliable use of lithium-ion battery, the experts were very strict, careful design of battery safety, in order to achieve the the battery safety assessment indicators.
(1) diaphragm 135 ° C Automatic shutdown protection
Using the international advanced Celgard2300PE-PP-PE three-layer composite film. In the case of the battery temperature reaches 120 ° C, PE film on both sides of the composite membrane hole closed, the internal resistance of the battery increases, the battery internal temperature mitigation, when the battery temperature reaches 135 ° C, PP film hole is closed, the internal battery disconnection, the battery is no longer warming, to ensure safe and reliable battery.
(2) additives are added to the electro-hydraulic
Overcharge the battery, the battery voltage is higher than 4.2v conditions, the electro-hydraulic additives and other substances in the electro-hydraulic polymerization mate increase in the internal resistance of the battery, disconnection of a large area inside the battery, the battery is no longer heating up.
(3) The battery cover composite structure
The battery cover with the notch explosion-proof structure, the battery temperature, the expansion part of the gas generated in the battery internal activation process, the battery internal pressure increase, the pressure reaches a certain degree notch rupture and bleed.
(4) a variety of environmental abuse test
Various abuse tests, such as an external short circuit, overcharge, acupuncture, plate impact, incineration, examine the safety performance of the battery. The battery temperature shock test and vibration, drop, shock and other mechanical properties test, study the performance of the battery in the actual use of the environment.
The lithium-ion battery is a new green battery
Care for the environment, protect the earth, "is the bounden duty of every one of us. How our environmental philosophy reflected in action?
Battery consumers should buy, the use of new green battery; battery manufacturers should produce new green battery. Only through our joint efforts to create, protect our beautiful and harmonious natural environment.
The new green battery means in recent years has been put into use or being developed by a class of high-performance, non-polluting batteries. Already extensive use of lithium-ion batteries, nickel metal hydride battery, and are promoting the use of mercury-free alkaline manganese batteries and plastic being developed lithium or lithium ion batteries, fuel cells, electrochemical storage super capacitor is a new type the scope of the green battery. In addition, has been widely used for the use of solar performs photoelectric conversion of the solar cell (also known as photovoltaic power generation), also belong to this category.