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[Group] Steel hull / aluminum / cylindrical / flexible packaging series: ------------------ 1 [positive] Active substances for the manganese lithium or lithium cobalt oxide, appeared nickel cobalt manganese lithium materials, electric bicycles are generally nickel cobalt manganese lithium (commonly known as ternary) or three yuan a small amount of lithium manganese oxide, pure manganese lithium and lithium iron phosphate gradually fade due to the large volume, poor performance or high cost. Electrolytic aluminum foil conductive collector with a thickness of 10 - 20 microns ------------------ 2 [diaphragm] A special molding the polymer film, the film has a microporous structure that allows lithium ions to pass through freely, while the electronic is not passed. ------------------ 3 [negative pole] The active material is graphite, or approximate the graphite structure of the carbon, a conductive collector using a thickness of 7-15 microns, electrolytic copper foil ------------------ 4 [organic electrolyte] Carbonate-based solvent, a polymer dissolved lithium hexafluorophosphate gelled electrolyte is used ------------------ Battery case 5. [] Divided into the steel shell (the square now rarely used), aluminum, nickel-plated iron shell (cylindrical battery use), aluminum-plastic film (flexible packaging), as well as the battery cap battery positive and negative terminations ======================== [Deconstruction principle ------------------ [Summary] The lithium battery is divided into lithium and lithium ion batteries. Mobile phones and laptops are used in lithium-ion battery, it is commonly known as a lithium battery, real lithium batteries due to risk, rarely used in everyday electronics. ------------------ [Mechanism] The lithium ion battery as the carbon material as a negative electrode, a lithium-containing compounds as the positive electrode, there is no lithium metal present, only the lithium ion, which is a lithium ion battery. The lithium-ion battery is the general term for lithium ion intercalation compound as a cathode material for battery. The charging and discharging process of the lithium-ion battery, lithium ion intercalation and deintercalation processes. In the process of intercalation and deintercalation of lithium ions, accompanied with equivalent lithium ion intercalation and deintercalation of the electron (customary positive electrode with embedded or de-embedded, said negative electrode inserted or de-inserted shown). The process of charging and discharging, the lithium ions between the positive and negative and from embedded / deintercalation and insertion / off plug, aptly called "rocking chair battery. ------------------ Work status and efficiency] The lithium-ion battery energy density, the average output voltage is high. Low self-discharge, good battery, less than 2% per month (resume). There is no memory effect. Wide operating temperature range of -20 ℃ to 60 ℃. Cycle superior performance, fast charge and discharge, charging up to 100% efficiency and power output. Long service life. Contain toxic and hazardous substances, known as the green battery. ------------------ [Charging] Rechargeable battery reuse steps, lithium-ion battery charging process is divided into two stages: constant current fast charge phase and voltage current phase. Constant current fast charge phase, the battery voltage is gradually increased to the standard battery voltage, followed by the control chip into the constant voltage phase, the voltage will not rise to ensure that you do not over-charge current gradually weakened with the rise of the battery to the set values, and the final charge. Statistics chip power consumption by recording the discharge curve can calculate the sample battery power. Lithium-ion batteries in repeated use, the discharge curve will change, although there is no memory effect, lithium-ion batteries but charge, discharge improper seriously affect battery performance. ------------------ [Charging Precautions] Excessive lithium-ion battery charge and discharge will cause permanent damage to the positive and negative. Excessive discharge of the negative carbon lamellar structure collapse, and collapse will be caused by the process of charging the lithium-ion can not be inserted; The overcharging excessive lithium ions into negative carbon structure, caused part of the lithium-ion no longer be released. The charging amount is equal to the charging current multiplied by the charging time, charge control under certain voltage, the greater the charge current (charging faster), the smaller the charge gauge. Battery charging excessive speed and improper termination of the voltage control point, and will also result in insufficient battery capacity, the the actual battery electrode active material did not get a good reaction stop charging, this charging phenomenon is exacerbated by the increase of the number of cycles. ------------------ [Discharge] Is forced into the predetermined first charging and discharging, if time can be longer (typically 3 - 4 hours is sufficient), it can make the electrodes as much as possible of the highest oxidation state (fully charged), the discharge (or use) voltage, or until the automatic shutdown, so can activate the battery capacity. However, in the normal use of the lithium ion battery, do not need to do so at any time according to need to be charged when charging is both unnecessary necessarily fully charged, and do not need to discharge. Like the first charge and discharge as operating only every 3 - 4 months, 1 - 2 times consecutive. ======================== Works When charging the battery, the positive electrode of the battery, lithium ions generated, the resulting lithium ion movement through the electrolyte to the negative electrode. As a carbon of the negative electrode was a layered structure, it has a lot of pores, reaching the negative electrode of lithium ions embedded into the porous carbon layer, embedded in a lithium ion is more, the higher the charging capacity. Similarly, when the discharge of the battery (ie battery), embedded in the the negative carbon layer in the lithium-ion prolapse, and movement back to positive. Back to the positive electrode of a lithium ion, the more the higher discharge capacity. General lithium battery charge current is set between 0.2C to 1C, the greater the current, charging the faster the battery heating. Moreover, an excessively large current charge, the capacity is not enough full, takes time because the electrochemical reaction inside the battery. Told poured beer down too quickly, then foam, but discontent. The battery for normal use, the discharge process. Lithium battery discharge points to note: Discharge current can not be too large, too large current battery internal heat, may cause permanent damage. Phone, this did not make the problem can not be considered. 2. Definitely not over discharge! Lithium batteries are most afraid of over-discharge, the discharge voltage is lower than 2.7V, will likely lead battery scrap. Fortunately, mobile phone batteries are already installed to the protection circuit, the voltage is not low to damage the battery level, the protection circuit will function to stop the discharge. As can be seen from the diagram, the battery discharge current is larger, the smaller the discharge capacity and the voltage drop faster. ======================== [Advantages] ------------------ 1 [high voltage] Monomer battery voltage up to 3.7-3.8V (lithium iron phosphate is 3.2V), the Ni-Cd, Ni-H battery 3 times ------------------ 2 [energy] The actual ratio of the energy of current to achieve about 555Wh/kg, i.e. the material can reach the specific capacity of 150mAh / g or more (3 - 4 times in a Ni-Cd, 2 - 3 times in a Ni-MH), already close to its approximately 88% of the theoretical value. ------------------ 3 [long cycle life.] General can reach more than 500 times, even 1,000 times more than lithium iron phosphate can reach more than 2000 times. For small current discharge of electrical, battery lifespan, doubling the electrical competitiveness. ------------------ 4 safety performance] Pollution-free, no memory effect. Predecessor as Li-ion lithium battery, lithium metal is easy to form a short circuit of the dendrite, reduced its applications: Li-ion does not contain cadmium, lead, mercury and other environment polluting elements a major drawback: the part of the process (sintering), Ni-Cd battery existence of the "memory effect", has severely constrained the use of battery, Li-ion problem does not exist in this regard. ------------------ 5 self-discharge small] Room temperature full charge the Li-ion storage 1 month after the self-discharge rate of about 2%, significantly lower than 25-30% of the Ni-Cd, Ni, the MH in 30-35%. ------------------ 6. [Fast charge and discharge The 1C charging capacity of 30 minutes can reach more than 80% of the nominal capacity, phosphorus iron battery up to 10 minutes to charge to 90% of the nominal capacity. ------------------ 7. [Operating Temperature Range Operating temperature -25 ~ 45 ° C, and look forward to widening -40 to 70 ° C with the improvement of the electrolyte and cathode. ======================== [Disadvantage] ------------------ 1 [feeble old] Unlike other rechargeable batteries, lithium-ion battery capacity will slow recession, regardless of the frequency of use and temperature related. The possible mechanism is gradually increased internal resistance, high current electronic products easier embodies. Replaced with lithium titanate graphite seems to prolong life. Storage temperature and capacity of the permanent loss of speed | Rechargeable power storage temperature 0 ° C | storage temperature of 25 ° C | storage temperature of 40 ° C | storage temperature of 60 ° C | 40% 60% 2% / 4% / 15% / 25% / year 100% 6% / 20% / 35% / 80% / June ------------------ 2 [recoveries] Approximately 1% of the new factory for various reasons, need to be recycled. ------------------ 3. [Highly intolerant charge] Overcharge, excess lithium ions embedded permanently fixed in the crystal lattice, can no longer be released, can result in short battery life. ------------------ . Highly intolerant put] Overdischarge, the electrode deintercalating excessive lithium ions, can lead to lattice collapse, thereby shortening the life. ------------------ 5. Multiple protection mechanisms [] Due to incorrect use will reduce the life, and may even result in an explosion, so a variety of protection mechanisms in the design of the lithium-ion battery. ------------------ 6. Protection circuit Prevent overcharge, over-discharge, overload, overheating. ------------------ 7 [vent] Because of their anti-explosion function, the battery industry insiders also known as explosion-proof the hole or explosion-proof line. The principle is very simple, the surface of the casing to draw a line or hole is slightly thinner than the thickness of the casing surface, when the batteries is short-circuited, the battery internal short time will produce large amounts of gas and rapidly increasing the pressure, when the pressure overload, a result of the explosion-proof holes thinner than the rest of the shell, the gas explosion hole discouraged, so as to achieve to avoid the risk of explosion of the batteries overall. ------------------ 8 [diaphragm] Isolate the batteries positive, negative film to prevent the core internal positive and negative film in direct contact to cause a short circuit; from the microscopic point of view, the the diaphragm surface mesh structure, usually PP, PE, there are PE, PP composite with . Distinguish diaphragm are usually divided by the thickness, width, thickness of the aluminum lithium-ion batteries use a diaphragm usually 16um, 18um, 20um, etc., power battery using a separator above 30um thickness for the mainstream. In terms of shape distinguish roll strip divided. The the roll diaphragm is the cutting width of the diaphragm, volume in a cardboard tube for customers cut their own the diaphragm a single length (similar to the shape and transparent plastic). Length, width, thickness and other parameters, strip diaphragm by the supplier by customers directly crop good diaphragm into strips. Roll separator advantage of versatility, but the need to increase the human crop strip diaphragm advantage without human cutting can be used, but not strong versatility. The battery internal temperature is too high, the diaphragm can melt to prevent the explosion of the battery. When the battery internal temperature reaches 130 ° C (lithium ion battery national standards gb18287-2000) above, the mesh holes of the diaphragm will be closed to prevent the lithium ions by the increased internal resistance (to 2kΩ), and continue to prevent the internal temperature of the batteries in order to achieve l high, thereby protecting the batteries to produce a risk of explosion. Vent diaphragm Once activated, the battery will be permanently disabled. ======================== 【Note】 Avoid use in severe conditions, such as: high temperature, high humidity, long hours under the summer sun exposure and so avoid the battery into fire Remove the battery, should ensure that the electrical appliances in a power-off state; temperature should be maintained between -20 ~ 50 ℃ Avoid the batteries long time "storage" stop using electrical appliances ======================== 【Network reprint / Just reference】 【Translation is by Goolge】 |
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