In the automotive industry for 15 years + practitioners, he worked in the products, markets, brands, communications and other departments of many German, American and Japanese car companies. He once had many identities and titles: “Brand Manager” and “Technical Enthusiasts”, and the nickname “Fa Ge” was the first winter in the industry. As an old bird, I have experienced too many ups and downs in the Spring and Autumn Period. Now I want to share more about knowledge and experience. I also have some time of my own. I hope to help everyone and hope that the car circle is getting better and better.
Electric vehicles have become hotter and hotter in recent years. I know that there are a lot of brands and products in the discussion. I will throw a brick here and spend some time talking about the battery. Please also bear with me. The principle is: ask simple questions, say simple In the case of a simple example, I also added an audio after the text. I don’t want to read the words directly to the final dry goods.
First focus: power battery and mobile phone battery are lithium-ion batteries, the working principle is similar, but different types are different from mobile phone batteries, power battery is high-voltage battery, high energy density, storage energy multi-power battery is divided into square according to shape Round and soft packs; batteries with different shapes and materials such as ternary lithium, lithium iron phosphate, and lithium cobalt oxide according to the positive electrode materials have their own advantages and disadvantages, and determine the battery performance, endurance, life, safety and other factors. It is a battery core, a battery module, and a module with other components. The battery pack/system is essentially a lithium-ion battery. The flow between the positive and negative electrodes of the battery to complete the charging and discharging process
Lithium-ion power battery works (picture from: Ningde era CATL)
Power batteries are not as compact and light as mobile phones and household batteries. They are bulky, more complex in structure and technology. At the same time, compared with other batteries on passenger cars, power batteries have many characteristics: large capacity and high energy density. , high voltage, etc., usually the voltage can reach 300-400V, the stored electric energy can reach tens or even hundreds of kilowatt hours, and the weight can reach several hundred kilograms or even heavier.
The car manufacturer will choose different types of batteries according to the performance, endurance, life, safety, cost and price of the production car.
First, the shape
Like the mobile phone battery, in order to plug the power battery into different models, the battery "shape" is also various. In the "external" shape, the battery has three types: square, cylindrical and soft.
Among them, the square battery is the mainstream and trend of the industry, and all major automobile companies and battery manufacturers have invested a lot in this aspect. Because of the characteristics of its design structure, the battery core is relatively safe and stable, easy to control temperature, discharge pressure and explosion; at the same time, the shape of the square is also easy for battery manufacturers to take advantage of raw materials, achieve higher energy density, and easy to meet the needs of models and chassis. Combine, so many car companies will use different numbers of square battery modules to adapt to their different models.
The cylindrical battery was born very early. Taking the 18650 battery (in fact, the traditional No. 5 battery) as an example, its production stability has advantages. The brands are more Japanese manufacturers like Sony, Panasonic and LG. The commonly used mobile phone charging treasures are basically cylindrical batteries. However, the volume utilization of cylindrical batteries is relatively poor. Think about it. Even if the stickers are close, there must be a gap between every four batteries. Because of the small size, each battery can carry less energy, and the number of electric vehicles needs to be used. Therefore, the requirements for BMS thermal management are relatively higher.
Soft pack batteries are also a type of power battery, and some electric vehicles also use such batteries. The form of the soft bag is also widely used in mobile phones, and has the characteristics of small size, light weight, and relatively high energy density. But also because of the compact size, the electrolyte can flow freely in the soft bag, and the ultimate compression volume, reduce the thickness, although it can be done very thin, but the requirements for heat dissipation and safety are relatively high.
Comparison of advantages and disadvantages of several batteries:
The battery mentioned above is strictly called the battery core. It is the smallest unit in the battery. Multiple batteries form a module, and multiple modules are combined with other components such as cooling system, power management system, bottom case and top cover. Generally speaking, the battery is strictly called "battery pack or battery system", while the battery is called "three electric" with the motor and electric control. They constitute the most important part of the electric vehicle powertrain.
Third, summary
Therefore, when you buy an electric car, it is recommended to pay attention to whether the power battery has both "face value and strength", that is, the shape of the battery and the positive electrode material, because they determine the performance, endurance, safety and cost of the battery. Factors that directly affect the experience of electric vehicles
