cr2032 button battery.Detailed introduction to the classification, advantages and breakthroughs of new energy batteries

In the past few years, with the rapid growth of new energy vehicle production and sales, my country's power battery industry has made great progress. The core component of new energy vehicles is the vehicle power battery, which is the energy source of new energy vehicles and directly determines the vehicle's cruising range.

In the past few years, with the rapid growth of new energy vehicle production and sales, my country's power battery industry has made great progress. The core component of new energy vehicles is the vehicle power battery, which is the energy source of new energy vehicles and directly determines the vehicle's cruising range.

New energy vehicle battery

In the past few years, with the rapid growth of new energy vehicle production and sales, my country's power battery industry has made great progress. The core component of new energy vehicles is the vehicle power battery, which is the energy source of new energy vehicles and directly determines the vehicle's cruising range.

China's power battery market is dominated by local companies, and the corporate structure is clearly stratified. It is mainly divided into four echelons according to technical level and market performance. The first echelon companies BYD and CATL are technologically leading, and the scale effect has led to significant cost reductions. In the competition Take an absolute advantage.

Ternary batteries and lithium iron phosphate batteries are both dominant applications in the fields of passenger cars and commercial vehicles. Currently, passenger car batteries are mainly ternary batteries, and commercial vehicle batteries are mainly lithium iron phosphate batteries.

Classification of new energy batteries

1. Lead-acid battery

As a relatively mature technology, lead-acid batteries are still the only battery for electric vehicles that can be mass-produced due to their low cost and high-rate discharge capability. During the Beijing Olympics, there were 20 electric vehicles using lead-acid batteries to provide transportation services for the Olympics.

However, the specific energy, specific power and energy density of lead-acid batteries are very low, and electric vehicles using this as a power source cannot have good speed and cruising range.

2. Nickel-cadmium batteries and nickel-metal hydride batteries

Although their performance is better than lead-acid batteries, they contain heavy metals and will cause environmental pollution after use and disposal.

Nickel-metal hydride power batteries have just entered a mature stage and are currently the only battery systems used in hybrid vehicles that have been actually verified and commercialized and scaled. 99% of the existing hybrid battery market share is nickel-metal hydride power batteries, and commercial The representative of globalization is Toyota's Prius. At present, the world's major automotive power battery manufacturers include Japan's PEVE and Sanyo. PEVE occupies 85% of the global market share of nickel-metal hydride batteries for hybrid power vehicles. Currently, the main commercial hybrid vehicles include Toyota's Prius, Alphard and EsTIma. And Honda's Civic, Insight, etc. all use PEVE's nickel-metal hydride power battery packs. In our country, Changan Jiexun, Chery A5, FAW Pentium, GM Grand Hyatt and other brand cars are already in demonstration operation. They also use nickel-metal hydride batteries. However, the batteries are mainly purchased from abroad. Domestic nickel-metal hydride batteries are used in automobiles. Still in the R&D matching stage.

3. Lithium battery

Traditional lead-acid batteries, nickel-cadmium batteries and nickel-metal hydride batteries are relatively mature in technology, but there are major problems when they are used as power batteries in cars. At present, more and more automobile manufacturers choose to use lithium batteries as power batteries for new energy vehicles.

Because lithium-ion power batteries have the following advantages: high operating voltage (3 times that of nickel-cadmium batteries and hydrogen-nickel batteries); large specific energy (up to 165WH/kg, three times that of nickel-hydrogen batteries); small size; light weight ; Long cycle life; low self-discharge rate; no memory effect; no pollution, etc.

Currently, many well-known automobile manufacturers are committed to developing power lithium battery vehicles, such as Ford and Chrysler in the United States, Toyota, Mitsubishi, Nissan, Hyundai in South Korea, Courreges and Venture in France, etc. Domestic car manufacturers BYD, Geely, Chery, Lifan, ZTE and other car companies have also equipped their hybrid and pure electric vehicles with power lithium batteries.

The current bottlenecks hindering the development of power lithium-ion batteries are: safety performance and the management system of automobile power batteries. In terms of safety performance, due to the high energy density, high operating temperature, harsh working environment and other reasons of lithium-ion power batteries, coupled with the people-oriented safety concept, users have put forward very high requirements for battery safety. In terms of the management system of automobile power batteries, since the working voltage of automobile power batteries is 12V or 24V, and the working voltage of a single power lithium-ion battery is 3.7V, multiple batteries must be connected in series to increase the voltage, but it is difficult to do this due to the battery Completely uniform charge and discharge, so a single battery in multiple battery packs connected in series will have an unbalanced charge and discharge situation, and the battery will appear undercharged and overdischarged, and this situation will lead to a sharp deterioration of battery performance, and ultimately As a result, the entire battery pack cannot work properly or even be scrapped, which greatly affects the service life and reliability of the battery.

4. Lithium iron phosphate battery

Lithium iron phosphate battery is also a lithium battery. Its specific energy is less than half that of lithium cobalt oxide battery, but it is highly safe, can cycle up to 2,000 times, has stable discharge, and is cheap, making it a new choice for vehicle power.

Industry insiders believe that the iron battery proposed by BYD is likely to be a lithium iron phosphate battery.

5. Fuel cells

Simply put, a fuel cell (FuelCell) is a power generation device that directly converts chemical energy present in fuel and oxidant into electrical energy. Fuel and air are fed into the fuel cell respectively, and electricity is wonderfully produced. It looks like a battery with positive and negative electrodes and electrolytes, but in fact it cannot store electricity but is a power plant.

The most promising one for automobiles is the proton exchange membrane fuel cell. Its working principle is: send hydrogen to the negative electrode, and through the action of the catalyst (platinum), two electrons in the hydrogen atom are separated. Under the attraction of the positive electrode, these two electrons generate current through the external circuit, and the hydrogen that loses the electrons Ions (protons) can pass through the proton exchange membrane (i.e., the solid electrolyte) and recombine with oxygen atoms and electrons at the positive electrode to form water. Since oxygen can be obtained from the air, as long as hydrogen is continuously supplied to the negative electrode and water (steam) is taken away in time, the fuel cell can continuously provide electrical energy.

Because the fuel cell directly converts the chemical energy of the fuel into electrical energy without going through the combustion process, it is not limited by the Carnot cycle. At present, the fuel-electricity conversion efficiency of fuel cell systems is 45% to 60%, while the efficiency of thermal power generation and nuclear power is about 30% to 40%.

New energy vehicle battery breakthrough (power battery)

In the past year, the electric vehicle industry has been transforming towards high-quality development, and the situation is very gratifying. On January 7, on the eve of the Diaoyutai Forum held by the China Electric Vehicles Committee of 100, Chen Qingtai, chairman of the China Electric Vehicles Committee of 100, said in an interview with a reporter from the 21st Century Business Herald.

The main manifestations of the transformation of high-quality development are: forward development has almost completely replaced reverse development, innovation capabilities have continued to improve, and the overall technical level has reached a great level; the acceptance of electric vehicles by users and the market has increased rapidly; major products From mid- to low-end to mid-to-high-end, some have proposed targeting high-end cars and luxury brands.

At the same time, while the world's major automobile companies are rushing to announce their transition to electric vehicles, my country's electric vehicle industry system is gradually improving. The main components, especially power batteries, have always maintained world-class standards, and the level of main components and supporting capabilities have improved. soon.

The price-performance ratio will exceed that of fuel vehicles

In 2017, the cumulative sales of new energy vehicles in my country from January to November were 609,000 units, a year-on-year increase of 51.4%, just one step away from completing the annual target of 700,000 units. Some experts predict that the sales data for December have not yet been released, but the total sales of new energy vehicles in 2017 may exceed 800,000 units.

The further development of electric vehicles has to cross a critical point, that is, the cost performance of electric vehicles reaches or exceeds that of fuel vehicles. If this threshold is crossed, electric vehicles can develop independently relying on market forces. Now they have to rely on policies and government subsidies. . Chen Qingtai told reporters that when financial subsidies are completely cancelled, the dual-point policy will be used as an alternative policy, and the points proportion for new energy vehicles will continue to increase on the basis of 12% in 2020.

When will this critical point occur? Chen Qingtai’s judgment is that it will be around 2025.

In this regard, Chen Qingtai suggested that car companies should be prepared in the following aspects: first, do a good job in ensuring sustainable development after the financial subsidies are reduced. In addition, the electric vehicles themselves should improve their cost performance through lightweighting and energy conservation; Secondly, product technology must have two specialties. One front is to improve the driving function of the car, and the other front is to apply intelligent network connection and sharing to new energy vehicles; thirdly, autonomous driving is a commanding height in the future; Fourth, we must hurry up and do brand building in the limited time.

At the same time, with the deep integration of the automobile industry with new technologies such as electrification, intelligence, and informatization, a large number of new car manufacturing companies have emerged in my country. From following to influencing the world, China's automobile industry is embarking on a path from a major automobile country. The road to becoming a powerful automobile nation.

To truly gain a global foothold in electric vehicles, or to develop our own characteristics, it will be useless if we rely entirely on electrification. It will be difficult to do better than traditional cars. But if we can work hard in areas such as connectivity, intelligence, and shared travel, it is entirely possible to win, because this is our strength. I very much hope that Internet companies will enter the electric vehicle industry in a big way, share this piece of cake, and change the genes of traditional cars. Chen Qingtai said.

However, Ouyang Minggao, executive vice chairman of the China Electric Vehicles Association of 100, emphasized that although the core technologies of electric vehicles are usually batteries, motors, and electronic controls, for OEMs, they are more about branding and technology. , integration of marketing services.

Compared with traditional cars, this is particularly obvious in electric vehicles. The gap between Chinese car companies and foreign car companies is more reflected in comprehensive power consumption. Nissan's new generation Leaf can run more than 300 kilometers on electric power at 40 degrees Celsius under European working conditions, and can even run 400 kilometers under Japanese working conditions. The gap between our national car companies and them is still relatively large. Ouyang Minggao told reporters.

Power battery has a huge breakthrough in specific energy

Ouyang Minggao also said that my country's power battery technology has made substantial progress in 2017. The energy density of power battery systems has reached 150 Wh/kg or more, and the specific energy of a single lithium-ion power battery is expected to reach 300 watts by 2020. hour/kg target.

On March 1, 2017, the "Action Plan to Promote the Development of the Automotive Power Battery Industry" (hereinafter referred to as the Action Plan) issued by the Ministry of Industry and Information Technology, the National Development and Reform Commission, the Ministry of Science and Technology, and the Ministry of Finance proposed the main goals for the development of power batteries. By 2020, The specific energy of the new lithium-ion power battery cell exceeds 300 Wh/kg; the system specific energy strives to reach 260 Wh/kg, the cost is reduced to less than 1 yuan/Wh, and the use environment can reach -30°C to 55°C, and can have 3C Charging ability. By 2025, the new system power battery technology will achieve breakthrough progress, with a single specific energy of 500 Wh/kg.

At present, domestic and foreign technology research and development are basically at the same level, but the core of lithium-ion batteries is safety. Ouyang Minggao said that in terms of special research on new energy vehicles, CATL New Energy, Tianjin Lishen, and Hefei Guoxuan have made major technological breakthroughs.

It is understood that the energy density of a single power battery in CATL has reached 304 Wh/kg, the cycle life is basically around 1,000 times, and all safety tests have passed; in addition, the cycle life and energy density of Lishen and Guoxuan teams are different from the target requirements. Not much.

However, the development of power battery technology in my country is uneven. Ouyang Minggao told reporters that the current research on power batteries in China can be summarized into four aspects: first, the monomer specific energy of 300 Wh/kg can be industrialized in 2020, but safety must be strengthened; second, as a long-term implementation The two types of new systems targeted, lithium-sulfur and lithium-air batteries, are currently progressing relatively slowly at home and abroad, with no breakthrough progress seen in 2017. Third, the R&D and industrialization of solid-state batteries continues to heat up, but is subject to the problem of solid/solid interface stability. Restricted by two major issues: the stability of the battery and the rechargeability of metallic lithium anodes, true all-solid-state lithium metal anode batteries have not yet matured, but there have been breakthroughs in lithium-ion batteries using inorganic sulfides as solid electrolytes; fourth, China is developing high-capacity lithium-rich cathodes. In terms of materials, some breakthroughs were made in 2017. Innovative lithium-ion batteries based on high-capacity lithium-rich cathodes and high-capacity silicon-carbon anodes are more feasible than lithium-sulfur and lithium-air batteries.

Based on this judgment, in 2020, my country's power battery cell energy density will reach 300 Wh/kg, specific power will reach 1,000 Wh/kg, cycle more than 1,000 times, and cost within 0.8 yuan/Wh; from 2020 to 2025, power The energy density of the battery cell can be increased from 300 Wh/kg to 400 Wh/kg, and the cost per Wh is reduced from 0.8 yuan to less than 0.6 yuan.

In 2025, the reasonable range of pure electric cars with general cost performance is 300-400 kilometers. But in 2030, the biggest technological breakthrough will be reflected in the electrolyte. Solid-state batteries will be industrialized on a large scale, and the specific energy of the battery cell is expected to hit 500 Wh/kg. In 2030, conventional cost-effective models should have a cruising range of more than 500 kilometers. Ouyang Minggao said.

The latest breakthroughs in car battery technology

Not long ago, a patent news released by Fisker Automobile in the United States attracted worldwide attention. It has developed a solid-state battery that can increase the endurance of electric vehicles to 804 kilometers with only 1 minute of charging time, and can Advances in materials and manufacturing technology will reduce the cost to one-third of conventional lithium batteries by 2020.

Solid-state batteries have also entered the field of vision of most people. In fact, in principle, they are the same as current liquid lithium batteries. The biggest difference is that the electrolyte becomes solid, and more charged ions are gathered in it by virtue of density and structural advantages. One end can conduct greater current, thus greatly increasing the battery capacity.

The most notable features of solid-state batteries are two. One is high energy density. Many laboratories have achieved 300-400Wh/kg, which is 2.5-3 times that of traditional lithium batteries. The other is that they are safer and eliminate the need for batteries to a greater extent. Burning hazards caused by accidents such as rupture or high temperature.

Of course, solid-state batteries also have shortcomings, which are generally low conductivity, large internal resistance, and slow charging speed. As for how the American Fisker car can charge for 1 minute and have a range of 800 kilometers, that is its core secret.

Generally speaking, if solid-state batteries can be truly industrialized and brought to the market at low cost, it will completely solve the core problem of the current popularization of electric vehicles, and new energy vehicles will truly kill gasoline vehicles.