Digital battery

Lithium-ion batteries is a new type of battery, it does not contain lithium metal in the charge-discharge process, only the lithium-ion in the positive and negative exchanges between the campaigns, the electrode and electrolyte not participating in the reaction. Lithium-ion batteries for energy densities can reach 300Wh / L, the density of the payload can reach 125Wh / L.

 

1, Principles of batteries

Lithium-Ion batteries, with charges reaction mechanism of the discharge pipe, the lithium ions between positive and negative electrodes embedded in a prolapse, shuttle to and from the internal VGP-BPS10 battery without the presence of lithium metal, lithium-ion batteries more security and stability. The reaction scheme and the formula of basic reaction is:

 

2, construction of piers

The positive is LiCoO2 batteries and more conductive adhesives, coated aluminum foil to form the positive plate, the negative electrode is a conductive layer of graphite as well as agents and adhesive coatings based on copper particles Graphite is now more advanced layers were negative using nano-carbon.

 

The mechanism of above reaction, the positive use of LiCoO2, LiNiO2, LiMn2O2 which this is a structure of LiCoO2 layer forms very stable crystal, but when away from LiCoO2 XLI, its structure may change, but if change depends on the X size. Through research has found that when X> 0.5, where the structure of Li1-XCoO2 expressed in extremely unstable and collapse occurs paralysis crystal, its outdoor performances of the end for the batteries overwhelming. Therefore, as part of VGP-BPS9 batteries must be controlled by limiting the charging voltage Li1-XCoO2 the value of X, the general tariff, the voltage does not exceed 4.2 V when X is less than 0.5, XCoO2-li1 then the crystal is always stable. C6 has its negative characteristics of its own, when for the first time after the LiCoO2 cathode of Li is sufficient to negative C6, when the discharge Li returned to the LiCoO2 cathode, but must be followed in a part of Li C6 remained negative, the heart of ensuring that the next charge and discharge embedding normal Li batteries otherwise overwhelming very short to ensure that there are part of the Li remained negative C6 The general threshold voltage by limiting the discharge to achieve. Therefore, the safety of lithium rechargeable batteries, the maximum voltage ≤ 4 .2 V, discharge lower limit voltage ≥ 2.5V.

 

3, the battery safety

Batteries for safety and design, materials and control of production processes in the production process is closely related to other factors. In IBM ThinkPad R51 battery charging and discharge process, the positive electrode potential anode materials are in dynamic change, with the voltage higher load, the cathode material (LixCoO2) the upside potential, the anode material for the insertion of lithium (LixC6) potential first down, then the potential emergence of a long platform, when the charging voltage is too high (> 4.2V) or because the negative electrode material of the surface density over the surface density of cathode material (C / A ratio) is low, excess lithium anode material, the cathode potential down rapidly and so the precipitation of lithium metal (in Under normal circumstances, it will not be the precipitation of lithium), it will be the performance of batteries and safety is a major threat. Potential changes see below:

 

In the matter has been defined circumstances, C / A too large, it will appear above the results. Instead, C / A is too small, the capacity is low platform, low cycle characteristics of the poor. Thus, in the production and transformation of the way to ensure the design of a good C / A ratio has become a key production and processing. Therefore, production must be controlled on the following aspects:

 

1. Materials handling anode

1) The large and ultra-fine powder with a particle size necessary for a complete separation, avoiding overheating local electrochemical reaction resulting from a negative reaction, to improve Dell Inspiron 1150 battery safety.

2) increasing the surface porosity, which can increase capacity by more than 10%, while C / A rate unchanged, security increased dramatically. Treatment led to the surface of anode materials for better compatibility with the electrolyte, and promote the formation of SEI film and stabilization.

2. Pulping process control

A) Process of pulping using methods and advanced technology of special chemical reagents, so that positive and negative slurry surface tension between the groups minimized. Improve the compatibility between the different groups to prevent the material in the mixing process “Reunion” phenomenon.

2) The time-based coating materials and spray the gap should be controlled to 0.2 mm below the surface of such a plate covered with smooth without particles, dents, scratches and other defects.

3) The suspension should be stored for more than 6 hours, the viscosity of the slurry remained stable in the Territories, slurry polymerization in a group phenomenon. Grout to ensure uniform distribution of positive and negative electrodes on the uniformity of the substrate, thereby improving the consistency of batteries, security.

 

3. The most advanced equipment for manufacturing chips

1) a pole piece can ensure stability and consistency of quality has greatly improved the uniformity of the F2024B battery pole piece, reducing the likelihood of the emergence of hazardous batteries.

2) monolithic plate coating machine exceeds the value of error density must be less than ± 2%, length of the plate and the size of the gap error must be less than 2 mm.

3) The rolls of the press roller cone and radial runout shall not be greater than 4μm, to ensure consistency of thick plates. The equipment must be equipped with a comprehensive collection of dust to prevent dust particles caused by the internal micro-batteries short-circuit, thus ensuring self-discharge performance of batteries.

4) cutting machine must be used as a knife-type cutting rolls cutting a continuous device, and cut the film is not quite there Yebian, burrs and other defects. The same device should be equipped with a comprehensive collection of dust, ensuring self-discharge performance of batteries.

 

4. Advanced Sealing Technology

At home and abroad square lithium-ion VGP-BPS8A batteries are sealed laser (laser) welding sealing technology, which prohibits the use of YAG (yttrium aluminum garnet) laser resonant cavity exposed to a source of bright light (usually the lamp nitrogen) to issue a bunch of inspired one frequency of light (λ = 1.06mm) was concentrated in an infinite number of refracted through the resonator, then concentrate on the Guidance cell alignment between the cylinder and the cover so that after the merger of affinity for one to reach the cover plate and the tube The objective of the merger sealing body. In order to achieve sealing welding, must contain the following elements:

1) It must be great energy, high frequency, focused performance monitoring and precision of the laser welding machine.

2) It must be applied to high precision laser welding of the shell and battery cover.

3) It must have a high degree of purity nitrogen uniform protection, especially aluminum batteries require high purity nitrogen, or aluminum surface will be difficult to produce molten Al2O3 (melting point 2400 ℃ ).

4) batteries and expansion control reasons

Lithium-ion batteries in the manufacture and use, there is often swelling of the phenomenon through the analysis and research are essentially two reasons:

Drowned in a lithium-ion led to changes in the thickness

Lithium rechargeable ion batteries where the anode from the cathode board prolapse, causing negative electrode layer spacing increases, but the swelling is, in general, the thicker apple iBook G4 14 inch battery, plus the amount of expansion.

 

2. Caused by the expansion process of poor control

During the manufacturing process, such as dispersion slurry, C / A than in discrete, temperature control directly affects the expansion of cells able batteries. Including water, because the rechargeable lithium formation of compounds with high carbon activity is very sensitive to water is a tug of chemical reactions. Gases produced by the reaction caused by the cell pressure is increased, an increase in the swelling behavior of batteries. Therefore, in production, in addition to dealing with the dehumidifier plate strict fluid injection in the process of dehumidification equipment should be used to ensure the dryness of the HR2% air, the dew point ( in the atmosphere of moist air due to temperature drop, so that the content of saturated water vapor began to condense when the temperature) is lower than -40 ℃. In very dry conditions, and taking fluids injected under vacuum, greatly reducing the chances of plates and electrolyte absorption.

5, aluminum and steel batteries comparison of the security

Aluminum over steel with high security benefits, the following is different from the pressure of the experience:

 

Note: The pressure is the pressure of batteries within the pressure (unit: kg), the data tables of a core electrical thickness (unit: mm) of steel can be considered to result internal pressure is very slow, while the internal pressure aluminum reaction was very acute. Therefore, from the thickness can be judged on the basis of battery internal pressure while the pressure of steel piles are often induced by the implicit hidden dangers. A steel model 063,448 batteries.

Battery frost and key technologies:

 

1. The main raw materials of design calculations, selection and matching

2. Gel batteries special plate design, formulation and manufacturing process

3. Colloidal formulation and preparation, the dispersion SiO2

4. Early loading or filling operation

5. New gel batteries for added power technology

 

1. The main raw materials, design calculations, selection and matching

 

Gel batteries, the need to report the positive and negative electrode capacity, the thickness of the partition size, plastic shell the size of support, including IBM ThinkPad T60 battery capacity and the plastic shell size of single cell the relationship between the parameters corresponding to a series of reasonable arrangement. In general, single-cell battery should be able to guarantee an effective space filling of acid amounted to 12-15 ml / AH to protect the battery in the amount of the effect of the adjustment of acid-containing gel.

 

A common problem is the use of sealed AGM batteries the standard plastic shell to act as a shell plastic gel battery, which is often caused by insufficient capacity or the battery open circuit faults in voltage and other issues. Another problem more common in domestic PE separators such as the use of private partitions instead of gel batteries, or use a sleeve of fiberglass, silk short sleeves instead of polyester gel battery box Dedicated partitions, which are most seriously affected product, life makes life / cost, but not worth the candle.

 

Users demands long battery life expectancy colloid required in the design and equipment selection, when it should be more stringent than the conventional design sealed Dell Latitude D520 battery, seal the pole to the growth and expansion of plate boundaries, etc., required in the structure must be considered and there should be corresponding measures, such as strength and size of pads and linings using a special pole structure, and enough interior space.

 

It is worth noting is how to prevent the assembly process in the break and short circuit group to protect the qualification rate of finished product.

 

2. Colloid plate special battery design, formulation and manufacturing process

 

Private plate gel batteries in particular, positive plate, and plate sealed classic comparison of the battery must be adapted to gel batteries (electrolyte) Special Requirements:

 

A, the requirements of colloid infusion: making the electrolyte in the hp F2024B battery is full all the corners;

B, to eliminate the polarization resistance increases due to the uneven increase in effect, require grid support structure design reasonable, hob, drying process reasonable and practicable;

C, regardless of recycling or floating charge to use, require long life, there is no thermal runaway phenomenon;

D colloidal form a network structure on the plates and separators and opening requirements of the porosity;

E, moreover, the actual conversion time of the battery in question.

 

3. Formulation of colloids and preparation process, SiO2 dispersion

 

A, first of all, is a gel battery needs to know the problems that the sony VGP-BPS2A battery needs to determine colloidal properties.

 

Council of the battery positive and negative active material in the electrolyte, after infiltrating the structure, you can get some inspiration.

 

Contrary to watch active substances of the structure and composition changes in the electrolyte after injection, the active material and electrolyte combination of regional, living matter was crystal - colloids (crystal structure of the glue) , sulfuric acid and water can freely enter the active substance through the diffusion of network structure of the territory, but the plastic changes of crystal structure depends largely on living material (lead dioxide or metal ) and lead sulfate (sulphate) conversion, while the sulfuric acid and water, and generate little to do with the reduction or can not be because the sulfuric acid or water to increase and decrease in moisture or frost. Therefore, life can always keep the stability of the structure. Thus, it can analogy to say that the sulfuric acid and water in the role of colloids: In the additive in the plastic front, followed by injection in the plastic, but should not be the structure of colloidal constructions.

 

Previous studies, often the chemical transformation of silica hydration —- begin to draw on the reversible reaction of water glass to understand the mechanism of the colloidal structure, and it is very easy to stick on the glass water and other resources, and even the two Silica gel hydration is a key step.

 

In fact, if the set colloidal structure of sulfuric acid and water are the structural components, toshiba PA3285U-2BRS battery charge-discharge process in the corresponding chemical reaction caused by sulfuric acid and changes in the composition of water in the original colloidal structure will inevitably lead to fragmentation, collapse and reorganization, the correspondent must gel hydration and shrinkage. It is difficult to say that the battery life to meet the needs of a stable structure. Therefore, this myth should not be allowed to continue.

 

After that, we had an aging test (after festivals worldwide after the battery charge-discharge cycles, the crack formation) and gel batteries to overcharge and over discharge to verify this conclusion, a mainstream (0.2C to 0.3c) conducted on a full charge of battery power (1.5C to 3.0C), or excessive discharge and closing terminal battery voltage to 0V (discharge volume reached 1.2C to 1.5C, and even more). These experiences, we can see (police) for gel batteries warm, but we see no moisture to freeze.

 

B, the gel formulation and preparation, the more critical is the dispersion of silica. Not studied ultra-fine powder or knowledge, it is difficult to understand the dispersion of the dispersion of silica rigorous requirements. The ultra-fine powder technology in the industry of household batteries are not very partial knowledge of point to study the dispersion of silica dispersed in water is almost pitiful papers, research focussed mainly in paints, etc. Hang Dang.

 

C on silica thickening and thixotropy awareness, in particular, recognize that the thickening of the silica and thixotropy are not inalienable, a process of inappropriate preparation could affect the silica thickening and thixotropy. Right filling process of plastic production, the thixotropic gel is very important, but the life of the apple iBook G4 14 inch battery in the finished product, the colloidal thixotropic Zexu eradicated.

 

D, training battery, and the plate pairs of colloidal have different needs, a corresponding change in the colloidal components.

 

4. To start charging or filling operation

 

Many people are beginning to charge or recharge the battery capacity as a simple process to adjust and active substances in the process, prefer to be adjusted according to their understanding of recharge processes. In fact, the process of loading the gel battery is just a hammer 100 to 1000 the training process, each side in the process of loading and unloading steps is mutually reinforcing.

 

Enjoy the cooking equipment plate, the initial charge of battery for a complete charging process must address the following questions:

 

A plate active material fully translated to protect the battery capacity;

B, plate active material of structural adjustment in order to form a relatively homogeneous and colloidal;

C, reaching the original glue and sulfuric acid, water exchange, the formation of uniform colloidal structure, fully utilize and improve colloidal thickening, reduce the thixotropic gel to form a stable colloidal structure;

D set the Dell GD761 battery voltage and capacity, to adjust the consistency of the battery (capacity, resistance, voltage, etc. coherence).

E, charging additional water loss and water temperature control, and so on.

 

5. The new gel batteries add power technology

 

The new gel batteries, the aging treatment are not a new battery, because not yet formed cracks. Therefore, in the charging of fees to certain requirements.

 

Unreasonable electrical process may be more intense mixing effect, undermine the stability of the colloidal structure, hydration, once produced, it undermines the performance of colloidal thickening. After charging, it is easy to create a localized or overall hydration, this is a very serious damage to the gel, and it will significantly reduce the lifespan of the battery.

 

Stockpiles new gel properly shelved is also aging, can form cracks.

 

How the new batteries with gel methods are most rapid economic and environmentally sound treatment in the aging of the battery that is worth seeing.

Since 1992, benefits of Sony lithium-ion batteries to achieve industrialization since, under its high specific energy, long life, no memory effect, safe, reliable and can quickly load and unload, lithium-ion batteries are become the new power technology recent years, development of hot spots. Lithium-ion Dell Latitude D810 battery is the green environment-friendly pollution free rechargeable batteries meet environmental needs of national energy today in all areas of use of life is increasing rapidly. Currently, lithium-ion has been widely used in mobile phones, laptops, digital cameras, MP3 and other electronic products, many of replacing nickel-cadmium batteries and nickel-hydride batteries, metal, in applications such as most as an exclusive Jiucheng. In addition, lithium-ion battery electric vehicles in recent years, and some other high power batteries have started to come into practical use.

 

Before 2000, the Japanese lithium-ion batteries dominate the world, and production accounting for about 95%. In recent years, with China (including Taiwan) and the rapid rise of South Korea, the Japanese show a single model has been gradually broken. Market Share of Japanese lithium-ion batteries has fallen below 60%, about one third of the world to form a pattern. Although in 2008 the global financial crisis hit, but rechargeable batteries, regardless of volume, sales were both up there on the rise, but this year will continue to be a difficult year. The future, the rapid development of a variety of electric vehicles, lithium-ion batteries will become a major driving force for progress.

 

The status of lithium-ion batteries can not be shaken

 

In 1989, the small size of the room-type lithium batteries to achieve a practical use. However, in the summer over a series of batteries for cell phones use lithium overheating in 1989 and caught fire due to an accident in early 1990, the industry uses a cylindrical, hp F2024B battery Rechargeable lithium had a negative attitude towards the prospects for practical application. However, Sony has specialized in the manufacturing technology of energy batteries Sony (Sony Energy Tech) ’s courage to break the deadlock, the same year in February announced the lithium-ion rechargeable battery reached a practical level.

 

Cause of the accident caused by lithium batteries that will be used as anode material for lithium in the charge and repeated discharge, the cathode is the formation of dendritic crystals, so a short - circuit between the positive and negative electrodes, emitting smoke and fire. The lithium-ion rechargeable battery in the positive and negative do not use lithium metal and its positive use of LiCoO2 (lithium cobalt) alloy material, the negative electrode material using carbon type of coke. This ensures the safety of the Dell KD476 battery to reach the cylinders of lithium type.

 

However, the practice at the beginning of the performance of lithium-ion battery was not significantly better than the main competing products - Ni-MH rechargeable batteries. For example, in early 1993 lithium-ion rechargeable battery unit volume density of energy 220Wh / L (This is a diameter of 65mm and 18mm × length value of the cylinder type battery, the same below ), just over nickel-metal hydride batteries 180Wh / height of approximately 20 L%. In addition, lithium-ion rechargeable batteries, there are many shortcomings, such as “there is no tension between compatibility and dry,” the difficulties of load control “,” high resistance, current high charging and discharging can be, “difficult to parallel, it is difficult to realize large capacity battery” and so on.

 

However, mobile phones and video cameras and other manufacturers of lithium-ion rechargeable VGP-BPS9A/B battery features lights a little low. Energy density per unit weight of these terms, lithium-ion battery than nickel-metal hydride rechargeable batteries is about twice as high as up 115Wh/kg. In other words, the same energy capacity, lithium-ion battery reduces the weight by about half. Thus, manufacturers of portable equipment, under a special favor in 1991 after the adoption of lithium-ion rechargeable batteries have the product market, and very popular. Since then, Matsushita Battery Industrial Company in 1992, Japan’s Battery in 1993, Sanyo Electric, Hitachi and Canada Moli Energy (1990) were commissioned in 1994, established the lithium-ion rechargeable batteries in portable electronics on the market can not shake the position.

 

Since 1990, lithium-ion rechargeable batteries have been largely along the high density and secure the development of these two main lines. To promote the products of small and light, manufacturers of portable electronic equipment urged to improve the energy density of batteries. However, the denser the smoke of the fire, the greater the risk. Incident does not happen again! The summer of 1989 fire incidents in the apple A1060 batteryof technical persistent spirit: If an accident, the use of materials of lithium battery will be the future is doomed.

 

To this end, in lithium-ion rechargeable batteries, the beginning of practical use, the battery manufacturer for its implementation will be known as the “most protective” of strict security measures. In order to fall in poor operation of the battery due to excessive discharge / over charge of the state can ensure security, the manufacturer of the battery configuration of the three types of security architecture: PTC (positive temperature coefficient) thermistor valve Security diaphragm. When mounted detected an abnormal temperature, the possibility of cutting off the electric mode of the load cell to avoid the danger.

 

In addition, development of mobile phones, cameras, computer hardware manufacturers have to ensure mobile security battery has played an important role. At that time, all the hardware manufacturers have established programs for acceptance testing, such as nail prick test, high temperature / low temperature test, as well as heating pan tests. Equipment manufacturers will be a series of tests based on the results raise the existing problems in the toshiba PA3591U-1BRS battery manufacturer, on how to improve the cell structure and design of safety circuits, and so many points of view. In the hard work in close cooperation with the early 20th century during the period, lithium-ion rechargeable batteries are no longer a major accident, the market is developing very well.

 

Improved security, the lithium-ion battery energy density of the battery continues to increase. The beginning of practical use in 1990, lithium-ion battery density of energy per unit volume, but 190Wh / L to 19 years later, in 2009, this value increased about 4 times, reaching 740Wh / L. But the same period, the microprocessor clock frequency up to 100 times the capacity of the DRAM is increased 250 times. Therefore, the rechargeable battery is also frequently called progress is too slow.

 

Increased energy density is mainly based on positive and negative materials to improve hp Pavilion dv4 battery of structural adjustment and improvement of manufacturing processes such as leather and complete been piecemeal. 19 years, there have been three times the material of great change, many, many times the energy density of high speed. The first took place in 1994 and 1995, the anode material of coke in a class of carbon materials, carbon, graphite type materials, this change so that the energy density has increased by about 20%. In the following 8 ~ 9 years, has maintained a positive use of LiCoO2, cathode graphite using a combination of such carbon material. The Change 2nd occurred in 2002 and 2003, the LiCoO2 cathode material in the LiCoO2 and Li (Ni-Co-Mn) O2 mixture of materials, the energy density of about 10%.

 

Is currently in 3rd period of change. The anode material is the reform candidate materials, including the type of silicon alloy, tin alloy and lithium three categories. An alloy of tin came in practical use. Sony introduced after the spring of 2005, the group of device battery has started to use this material. 14mm (diameter) x 43mm (length) of the unit cell volume of the energy density can reach 478Wh / L, compared to traditional materials, an increase of approximately 20% of the Dell Latitude D410 battery.

 

In January 2007, Matsushita Electric Industrial and Matsushita Battery Industrial through the use of certain types of materials such as alloy anode material, with successes to 740Wh / L energy density per unit volume. The company did not disclose the specific circumstances of this alloy material, until March this year, not mass production, it is expected that the near future or will be put to practice. In addition, the type of alloy of silicon and metal lithium as a cathode can significantly increase the energy density of batteries are also on trial.

 

After 2006, laptops and mobile phones and other products used in lithium-ion rechargeable batteries, the recurrence of an abnormal occurrence of heat, the potential fire hazard. Sony, Matsushita Battery Industrial, Sanyo Electric and other battery manufacturers have a large number of recycling batteries. The reasons are said to be mixed in the process of manufacturing powder metal, it is said to be load and unload equipment manufacturers in the management of misconduct. And equipment manufacturers face the cons, up another case of malfeasance.

 

In fact, the real reason not yet been identified. To this extent, must be carefully verified reason, understand that the resurgence ‘accident, the future is doomed, “the gravity of technical staff to learn both sides to ensure safety at all costs try to develop the spirit of time, work together to move forward together.