Digital battery

Introduction: Ni-MH battery based on the hydrogen storage alloy electrode replacement Ni-Cd Cd electrode and developed a new type of batteries of high capacity rechargeable alkaline, becoming green energy is aujourd ‘Today an important direction of development of a secondary Laptop battery. The advantage is a greater energy density than the energy of the Ni-Cd 1.5 to 2 times, and resistance to overcharge, no memory effect, the advantages long battery life and the absence of metal pollution of the environment CD unique, it is as a national “95″ major projects of high technology research. After years of research and development, Ni-MH battery has become the market for rechargeable batteries (particularly the market for mobile), advanced products, to form their own country have been established and emerging industries.

 

1 works of the Ni-MH battery

 

Ni-MH material of the battery anode is an alloy hydrogen storage, a hydrogen absorption and desorption can be reversibly alloy. It’s the early seventies developed a new type of functional materials, which, under certain conditions, alloy reversible storage of hydrogen can absorb or release large numbers of hydrogen, d ‘ such a singular performance was applied to hydrogen storage and purification, This alloy is used resulting in turn heat pumps, compressors, catalysts, hydrogen cars burning, the separation of isotopes of hydrogen and so on. Ni-MH Ni-Cd have the same positive, ie hydroxy-nickel oxide as positive electrode, negative alloy extremely hydrogen storage, between positive and negative electrodes are separated by a membrane, while electrolyte solution is formed by the KOH and LiOH. [1] Ni-MH IBM ThinkPad X60 battery electrode chemical reactions that occur are:

 

Loading, the reaction at the cathode: Ni (OH) 2 + OH → NiOOH + H2O + e

                    Negative reaction: M + H2O + e → MH + OH —

Discharge cathode: NiOOH + H2O + e → Ni (OH) 2 + OH —

                   Negative: MH + OH-→ H2O + M + e

 

When overcharging and over the discharge occurs when the following reaction:

 

Overload, the positive electrode: 4OH-→ 2H2O + O2 +4 e

 

Cathode: 2H2O + O2 +4 e → 4OH —

 

Was released, the cathode: 2H2O +2 e → H 2 OH 2 —

 

Anode: H 2 → 2-OH 2H2O +2 e

 

Loading, the positive Ni (OH) 2 into NiOOH, the water molecules in the alloy hydrogen storage negative electrode on the discharge, the decomposition of hydrogen atom VGP-BPS9/S adsorbed on the surface electrode to form hydrogen atoms adsorbed. And then spread to the internal alloy hydrogen storage alloy reacts with hydrogen storage to form metal hydrides.

 

Disclaimer, enter e NiOOH-Ni (OH) 2 metal hydride hydrogen atom diffusion on the inner surface of the formation of adsorbed hydrogen atoms, the recurrence of the electrochemical reaction of alloy storage of ‘hydrogen and water. Over-discharge, the cathode can be restored on the consumption of NiOOH has been completed (the Ni-MH batteries are generally designed to be more negative), while H2O will be restored in the nickel electrode.

 

Overload due to the anode can be oxidized Ni (OH) 2 became NiOOH, when the formation of OH-lost e-O2, O2 spread cathode catalyst, the alloy hydrogen storage to be formed e-OH-, is also may produce negative hydrogen compounds in water, heat, so that the toshiba PA3191U-4BRS battery temperature, but also reduce the internal pressure of the battery. As the alloy hydrogen storage on the anode has been saturated with the absorption of hydrogen can not absorb hydrogen, this time, the water molecules in the cathode on discharge shape H2, H2, and a catalyst in the alloy hydrogen storage to the cathode under the infiltration of water on the compound of oxygen.

 

2, Ni-MH battery manufacturing process of batteries

 

Ni-MH battery can be made alkaline button-shaped or cylindrical, so different cell types, its structure similar to Ni-Cd batteries, especially for the sandwich-like. Ni-MH alloys manufacturing battery storage of hydrogen are primarily the preparation, positive and negative form, a pole piece assembly and so on. A typical link type Ni-MH battery manufacturing process of the battery is as follows:

 

 

Alloys for hydrogen storage apple A1060 battery should have a storage capacity of hydrogen, the equilibrium pressure of hydrogen moderate (0.01-0.5 MPa), good chemical stability in alkaline solution, abundant resources, low price and so on. Developed alloy hydrogen storage can be divided into four groups. Who have been marketed only AB5-type alloy, its actual capacity reached 330mAh / g, close to the theoretical value (372mAh / g). AB2 Laves phase alloys type are the subject of further research, quality of light, high capacity Mg-based AB2-type alloy While interest in people, but its capacity fading fast in order to achieve practical standards still need some time. To improve the life of an alloy hydrogen storage and a fast charge and discharge properties, surface treatment of alloys and diversified. Introduce the method of preparation of alloys for hydrogen storage are mainly gas atomization, centrifugal melt-spinning method, such as directional solidification method.

 

Currently used primarily to improve the sintering and impregnating parameters to increase the size of the sintered nickel cathode specific capacity, improving the ratio of volume capacity of sintered nickel positive electrode of a maximum of 500mAh/cm3 [4 ], while Ni-Cd ordinary sintered nickel positive electrode The volume ratio of capacity is only 400mAh/cm3. Ni-Cd in general need to add a small amount of nickel in the positive electrode to increase the charging efficiency of nickel cathode, reducing its rate of expansion; Ni-MH TravelMate 290 battery anode instead of adding Zn and Co to achieve the same results, and improve the absorption capacity of hydrogen battery, the control cells increased internal pressure.

 

3, at home and abroad to present Ni-MH battery research

 

3.1 current domestic battery Ni-MH Research

 

China in 70 years began to explore alloy hydrogen storage LaNi 5 electrode materials for the research opportunity is to make the material LaNi 5 physical properties and chemical and electrochemical properties. So Po Helanfeili first alloy LaNi 5 pluralistic makes Ni-MH batteries, with its U.S. and Japan, represented by a few developed countries, has launched a competition Ni-MH battery research practices and industrial development, in the shortest period of time have a marketing of Ni-MH BTP-43D1 battery market. China is the United States and Japan in the industrial development after the first developing countries. In 1995, China produced 2 million (equivalent to AA-type) batteries, the output value 210 million yuan in 1996, produced 31.4 million in 1997, producing 52 million in 1998 produced 80 million , an increase very rapidly. Tianjin Peace Bay in 1998 from the Toshiba Corporation to introduce technology and equipment. In February 1999, Tianjin blue sky, Sanyo, Japan, were introduced by Toyota, Ni-MH basic cell production, with an annual productivity of 30 million euros, and the formation of the corresponding battery, the product Sanyo’s latest is high capacity, fast charge, high reliability of the Ni-MH, with the highest level of the world. Developed by the Institute of Tianjin 1400mAhAA battery 1A charge-discharge, 100% DOD, the cycle life of more than 1000 times. Recently, Ni-MH battery-electric vehicles has been classified as medium development goals focus on long-term battery. Ni-MH battery industry in China over other countries in terms of manufacturing process of battery or product quality, varieties, there are many problems, the battery is not strong in the competitive international market. For example, the square sealed batteries because of these difficulties, lack of matching domestic manufacturers of parts and components, is not automated, and therefore not marketed. The existence of national capacity Ni-MH battery is small, short life cycle of high pressure, the discharge voltage is low self-discharge rate of greater uniformity and reproducibility is poor gap. Assembly of mobile phone batteries in China, Japan represents about 60% of the VGP-BPS9/B battery. On the Ni-MH battery recycling work at home or in white. China every year about 10 million cell phone batteries and other uses of the battery must be recovered and foreigners have been mostly recycling.

 

But we also know that our materials Ni-MH rich in resources, as early as 863 plans have Ni-MH battery included in development projects, 863 high-tech achievements exhibition was successfully presented the results of Ni-MH Rechargeable. As we all know, the China Central Television broadcast EV trial operation. These facts show that electric vehicles will be new applications Ni MH, potential for considerable development.

 

3.2 Visiting Ni-MH battery research

 

Since the early nineties of the last century have developed rapidly since the advent of NiMH batteries. Japan Nomura Research Institute, according to statistical analysis, since 1997 the global market size of a small battery has exceeded 500 billion yen in lithium-ion battery LIB 2,000 million yen market (ranked 1), the The old Ni-Cd batteries account for about ¥ 180000000000 (has a dominant position dropped to No. 2), Ni-MH VGP-BPS13A/B battery of about the maintenance of ¥ 120,000,000,000 (ranked 3).

 

As mobile communications, computing and portable consumer products has gradually begun to integrate the urgent needs of small batteries, light and efficient. Consequently, high energy density (Wh / kg), small and slim lithium-ion batteries LIB and Lithium Polymer (Lithium Polymer) batteries in recent years to obtain long-term development. In this case, one wonders, while pollution of the environment without Ni-MH battery will be developed? Ni-MH is technological innovation to develop new markets, new technologies and new products continue to emerge indicates that he has a beautiful view.

 

Ni-MH battery has been placed since the advent of mobile communications and the market for mobile computing with the lithium-ion batteries and lithium-polymer batteries a lot on the market, the increasingly competitive market. Many Japanese manufacturers produce lithium-ion batteries and Ni-MH and the output is high, they began to be produced manufactures lithium-ion batteries and Ni-MH products on the market for the sale of conflict has been a sense that it is open to Ni-MH new markets necessary. For example, the annual world production of 1997 lithium-ion batteries, Ni-MH and Ni-Cd value of hp Pavilion dv4000 battery power more than 500 billion yen, of which only the output value produced by Japanese manufacturers were more 400 billion yen (80% above), Japan 5 The major manufacturers (Panasonic batteries, Sanyo Electric, Toshiba, Hitachi Maxell, and Furukawa Battery Co., Ltd.) in 1997, production of Ni-MH value of cell production of 106.8 billion yen, which represents the value of total world production of Ni-MH (1200 billion yen) to 89%. Industry Analysis Japan and predict the time pointed out that in mobile communications and mobile computing applications, the lithium-ion batteries and lithium-polymer battery will become a mainstream product, Ni-MH battery in the 21st century in the first 10 years of back-up energy of the electric machine direction, it will drive electric vehicles and hybrid electric vehicles produced areas of current application.

 

Technology of the United States Molyech Power System allows the use of sintered electrodes for Ni-MH battery high current charge and discharge, which opens up scope wider. In particular, require a wide range of temperatures, withstand high vibration and high drainage capacity from the scope of high power will be widely applied to new technologies, equipment, Ni-MH battery. The Ni-MH battery in future areas of application are far from limited to mobile communications and mobile computing applications, but also on light applications, such as professional equipment and power tools to the consumer video, wireless equipment technical vacuum, and portable equipment and so on. These applications cover a wide variety of specific applications, as large as communications equipment remotely, UPS systems and electric vehicles, power small electric bicycle, light, power and even beauty tools and so on .

 

According to Japanese industry, has recently published a statistical analysis of the data table on the turn of the century, Ni-MH analysis of the Dell HD438 battery market forecasts are correct. On the mobile communications market, sales of Ni-MH decrease from year to year, sales of batteries LIB gradually increased: in 1998, lithium-ion batteries and Ni-MH strong sales of flat and more 28% each, Ni-Cd battery, and other revenue accounting for 43.4% battery, in 1999, LIB accounted for 34.1%, Ni-MH fell to 25.5%, Ni-Cd decreased to 40.4% in 2000, LIB rose to 38.8%, Ni-MH decreased to 22.9%, Ni - Cd and so on up to 38.3%. Opening new markets for Ni-MH were imminent, the Japan-US Ni-MH are the manufacturers accelerate the development of Ni-MH technology.

 

4 AA Ni-MH future developments

 

Since the introduction of Ni-MH batteries, and high energy and power required majority of applications have largely replaced Ni-Cd batteries Expected over the next Ni-MH battery will be applied to a wider range of tools High-power power. The Ni-MH batteries are used in high temperature environments, and develop a smaller and more efficient 40Y6795 battery capacity for high temperature, high vibration, and high efficiency of energy products and equipment, as hybrid electric vehicles, electric bicycle visualization tools for vehicles, UPS, telecommunications equipment, computers and supplies, emergency power lighting. For example, MOLTECH being developed in the airbag the size of a sintered Ni-MH batteries for hybrid vehicles. Although Ni-MH batteries as power supply for portable electronics best use lithium batteries have been challenges, but recent technology of production of sintered Ni-MH batteries will become the future for sustainable, high power and harsh environments of the ideal food. 

 

Generally, Ni-MH of China battery technology to track more research, basic research is little originality is not enough, of intellectual property rights, patents not pay enough attention they must be improved. We must put the limited human, material resources and financial combine. Intensification of production, capacity to overcome difficulties, and providing technical integration, complementary advantages, and actively participate in international competition. Capacity Ni-MH batteries and related materials, standardization of development. According to the national conditions of China, the Ni-MH batteries in electric bicycles, electric tricycle, electric four-wheeled vehicles, and other electric bikes on the prospect of application is vast.

 

5 Conclusion

 

Can be used as a source of energy despite a variety of cells, but low energy density of lead acid batteries, Ni-Cd can not fundamentally solve the problems of pollution, safety of lithium batteries -ion batteries is not enough and the price is expensive, Na2S battery temperature is too high, the electric vehicle fuel cell may be the ultimate choice problems, there are still more expensive. Ni-MH battery is a green battery, no pollution, no maintenance, safe, high specific energy and specific power, life support high levels of performance and discharge, long cycle, so they can meet the performance requirements of the battery. Therefore, the Ni-MH battery has been recognized as the world of real-world applications in recent years, with the best engine of choice.