What is the definition of a power battery?

Battery technology is a great invention with a long and splendid history. English " battery " first appeared in 1749. It used for the first time by the inventor, Benjamin Franklin. At that time he used a set of series capacitor for electrical experiment.

In 1786, the Italian anatomist galvanic when doing the frog dissection, found that bioelectricity, and published in academic circles, in 1800, volta inspired by galvanic frog experiment, with copper, tin, salt water as material successfully invented the voltaic cell, in 1836, Britain's Daniel redesign "volt electric pile".

He use dilute sulphuric acid as the electrolyte, can solve the problem of the battery polarization, produced the first polarization, can balance current ─ copper zinc battery, say again "Daniel battery".

Of plant in 1860, the French invented the use of lead in battery electrodes, also is the predecessor of the battery; At the same time, the French lakeland and invented the zinc carbon batteries, battery technology to the field of dry cell.

Commercial began in dry cell battery technology, it is made up of the British heller invention in 1887, and mass production in the United States in 1896, at the same time, Thomas Edison iron nickel in 1890 rechargeable batteries, also the commercial production in 1910.

Since then, due to commercial drive, battery technology ushered in the era of rapid, Thomas Edison invented in 1914, alkaline batteries, Schlecht and Akermann invented in 1934 sintered plate nickel cadmium battery, Neumann, developed in 1947 sealed nickel-cadmium batteries, LewUrry (Energizer) in 1949 to develop a small alkaline battery, the age for alkaline batteries.

Since the 1970 s, the battery technology is affected by the energy crisis, step by step in the direction of the physical power supply development, in addition to 1954 in solar cell technology continues to progress, lithium battery and nickel metal hydride batteries are also gradually invented and commercial applications.

What is the power battery？

The difference between it and common battery

New energy vehicles power source is the main power battery on average. Power battery is actually for transportation tools provide a power supply of power source. The major difference between it and common battery as follows:

First, different nature

Power battery refers to the battery powered tools for transportation, generally is relative to the to provide energy for small batteries for portable electronic devices; And ordinary battery is a kind of anode materials for lithium metal or lithium alloy, using a battery, nonaqueous electrolyte solution as lithium ion rechargeable battery and lithium ion polymer battery. It is not the same.

Second, the battery capacity is different

Under the condition of the battery is made up of new, used to put all test battery capacity, general power battery has a capacity of around 1000-1500 mAh; And batteries capacity above 2000 mAh, some to 3400 mAh.

Three, different discharge power

A 4200 mAh power battery will power light can in a short span of a few minutes, but the batteries completely can't do that, so batteries discharge ability completely cannot be compared with the power battery. Power batteries and batteries biggest difference lies in its discharge power, high specific energy. Because the main purpose for automotive type batteries which power the energy supply, so compared with ordinary batteries have higher discharge power.

Fourth, different application

For electric vehicle drive power battery is called power batteries, including traditional lead-acid battery, nickel metal hydride batteries and emerging lithium-ion power lithium batteries, divided into power type power battery type power battery (hybrid) and energy (pure electric vehicles); Mobile phones, laptops and other consumer electronics products generally referred to as lithium batteries, lithium-ion batteries used to distinguish it from power battery for electric vehicle.

Power battery existing main types

Mainstream technology on the market at present is still in lead-acid battery, nickel metal hydride batteries, lithium batteries, and fuel cell technology is given priority to.

Lead-acid battery

Longest history in the application of lead-acid battery, most mature technology, is the lowest cost, the price of battery, has achieved mass production. Valve control type sealed lead acid battery (VRLA) became a important vehicle power battery, used in many European and American car companies on the development of EV and HEV, such as general, developed in the 90 s and 1980 s respectively Saturn and EVI electric cars and so on.

However, low specific energy lead-acid batteries, battery life is short, high self-discharge rate, low cycle life; Its main material, the weight of lead big, and may be produced in the process of production and recycling heavy metal pollution of the environment. So, at present the lead-acid battery is mainly used for ignition device when the car started, and electric bicycle and other small equipment.

Ni-Mh batteries

Nickel metal hydride (Ni/MH battery has a good resistance to overcharge, discharge capacity, there is no heavy metal pollution problems, and will not appear in the working process of the phenomenon of increase or decrease in electrolyte, can realize sealing design and maintenance free. Compared with lead-acid battery and nickel cadmium battery, nickel metal hydride battery has high energy, specific power and cycle life.

Its disadvantage is that the battery has a memory effect is poorer, and as charge and discharge cycle of hydrogen storage alloy gradually lose the catalytic ability, the battery internal pressure will gradually rise, affect the use of the battery. In addition, nickel metal expensive price, also lead to the high cost.

On the key materials, nickel metal hydride batteries is mainly composed of the positive and negative, the diaphragm and the electrolyte composition, is extremely nickel electrode (Ni (OH) 2);The cathode generally USES metal hydride (MH);Mainly for the liquid electrolyte, ingredient is potassium hydroxide (KOH).The research emphasis of Ni-Mh batteries, mainly on the anode materials is, its technology is quite mature.

Vehicle Ni-Mh battery has achieved its mass production and use, is a hybrid car up on the application of on-board battery types. The most typical representative of the current hybrid production scale biggest Toyota Prius. Toyota established PEVE joint venture with Panasonic company is currently the world's largest manufacturer of Ni-Mh power battery.

Now Ni-Mh batteries have dropped out of the mainstream current power battery, so why Toyota will also be opinionated to camp of Ni-Mh batteries?

This will have to say to the nickel metal hydride batteries: the biggest advantage of super durability!

Once America's most famous auto media consumer reports on a ten years after the first generation of prius has carried on the contrast test. Test results showed that the nickel metal hydride batteries of the first generation prius models after 10 years after the 330000 km, with the new data contrast, whether in fuel consumption performance and dynamic performance are kept at the same level, the hybrid system and Ni-Mh battery pack still work normally.

In addition, even in use after ten years to run 330000 kilometers, the first generation of prius, the nickel metal hydride battery pack that never happened, people ten years ago question for battery capacity attenuation will significantly affect the dynamics performance of fuel consumption and also did not appear. Thus, always rigorous conservative Japanese for nickel metal hydride batteries in love does have its unique reasons.

A fuel cell

Fuel cell is a kind of will exist in the chemical energy of the fuel and oxidant directly into electrical energy power generation device. Fuel and air were sent to the fuel cell, electricity is produced. It viewed from the outside is the cathode and the electrolyte, etc., like a battery, but it can't essentially "storage" but a "power plants".

Compared with ordinary chemical batteries, fuel cells can refuel, hydrogen is often added. Some fuel cells can use methane and gas as a fuel, but is usually restricted to use industrial area, such as power plants and forklift truck. Basic principle of hydrogen fuel cell is the reverse reaction electrolysis of water, the hydrogen and oxygen supply of anode and cathode respectively, hydrogen in the anode after outward diffusion and reaction of the electrolyte, excite electrons by external load to the cathode.

Hydrogen fuel cells working principle is: to hydrogen fuel cell anode (cathode), through the role of catalyst (platinum), electron in a hydrogen atom is separated out, lose electron hydrogen ions (protons) through the proton exchange membrane, to fuel cell cathode plate (anode), and electron is not through the proton exchange membrane, the electron, only through an external circuit, to fuel cell cathode plate, so as to generate an electric current in the external circuit.

Electronics to the cathode plate, combined with oxygen and hydrogen ions for water. Due to supply oxygen to the cathode plate, can be obtained from the air, so as long as constantly to supply hydrogen anode plate, to supply air cathode plate, and promptly take water vapor, can continually provide electricity.

Fuel cell electric, the inverter, controller and other equipment, power supply to the motor, then through the transmission system and drive axle drive wheel rotation, can make the vehicles on the road. Compared with the traditional vehicles, fuel cell vehicles energy conversion efficiency is as high as 60 ~ 80%, and for 2 ~ 3 times of internal combustion engine.

Fuel cell is hydrogen and oxygen fuel products are clean water, work itself does not produce carbon monoxide and carbon dioxide, sulfur and particulate exhaust. Therefore, hydrogen fuel cell car is a real sense of the word zero emissions, zero pollution cars, hydrogen fuel is perfect car energy!

The characteristics of hydrogen fuel cells:

1, no pollution, fuel cell no pollution to the environment. It is through electrochemical reaction, rather than the combustion (gasoline and diesel oil) or energy storage (battery), the most typical traditional back-up power solutions. Combustion will release like COx, NOx, SOx, pollutants such as gas and dust. As mentioned above, the fuel cell will only produce water and heat. If the hydrogen is produced by renewable energy, the cycle is complete does not produce harmful substance emission process.

2, no noise, fuel cell quiet operation, noise is about 55 db, at the level of people normal conversation. This makes the fuel cell is suitable for indoor installations, or have restrictions on noise outdoors.

3, high efficiency, fuel cell power generation efficiency can reach above 50%, which is determined by the transform properties of the fuel cells, directly convert chemical energy to electrical energy, heat energy and mechanical energy is required to make (generator) in the middle of the transformation.

4, The advantage of the hydrogen fuel cell car, no doubt, the disadvantages are obviously. With the progress of science and technology, once the development of the hydrogen fuel cells, such as security, the problem such as hydrogen storage technology has been gradually and gradually improve, cost question, however, is still the biggest bottleneck hindering the development of the hydrogen fuel cell car.

The cost of hydrogen fuel cell is 100 times that of the ordinary gasoline engine, this price is the market. Another filling station behind, is a set of hydrogen energy production and transportation network as the support, and the vast majority of countries in the world did not intend to energy and space to develop a kind of not commonly used systematized.

Especially hydrogen energy conversion rate is low, and will cause pollution in energy production. On the other hand is the construction requirements and cost is extremely high, filling stations require specialized equipment to meet the needs of the energy storage at low temperature. Currently only Japan, South Korea and the United States more filling stations in California, and this also is actually more decades.

In 2017, originally some of the fuel cell car market in silence as if suddenly has some recovery.

On the one hand, has always high hoped of pure electric vehicle battery technology upgrade continuously encountered bottleneck. And the range is too short and charging time is too long this two factors still restrict the prospect of new energy vehicles.

On the other hand, is in the field of fuel cell car in multiple price is rising.

Originally high fuel cell car is experiencing a rapid decline in production cost. Compared with in a state of competition in high-grade pure electric vehicles, 5 minutes to experience full of fuel and more than 500 km mileage of course attractive.

Lithium ion batteries

Automotive lithium ion power battery is developed on the basis of disposable lithium batteries, is currently the main direction of pure electric vehicle battery research and development. Lithium ion battery has no memory, low self-discharge rate, environmental protection, a lot of advantages, such as specific energy, specific power is after Ni-Mh batteries, the potential of the most popular with R&D and automakers onboard battery.

Lithium ion battery characteristics

1, the voltage platform

Lithium ion battery as the anode materials is different, its monomer battery voltage in the range of 3.7 ~ 4 v, the application of the larger lithium iron phosphate monomer battery voltage is 3.2 v, is 3 times of Ni-Mh batteries, lead-acid batteries 2 times

2, is greater than the energy

The current passenger car of lithium ion power battery energy density is close to 200 wh/kg, is expected to reach 300 wh/kg in 2020

3, short battery life

Due to the restriction of electrochemical materials properties, lithium ion battery cycles no breakthrough, in the case of lithium iron phosphate, monomer battery cycles can reach more than 2000 times, only after the group for more than 1000 times.

4, greater impact on the environment

Lithium ion battery uses light metal lithium, although do not contain mercury, lead, harmful heavy metals, is considered to be the green battery, less pollution to the environment.

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