Analysis of electric vehicle batteries: What is the structure of the heart of an electric vehicle? Where is the price increase?

With the steady development of the new energy market, the penetration rate of new energy vehicles in the market has continued to increase. Many car companies have also begun to put plans to gradually stop producing fuel vehicles on the agenda and shift their development focus to pure electric vehicles. However, judging from the current market situation, the development of new energy vehicles seems to have entered a bottleneck period. First, the problem of range anxiety has not been solved; second, with the growth of market demand, the upstream raw material industries of new energy have increased in price. And these problems all point to one place, that is, the battery of electric vehicles.

Batteries are familiar to everyone. From the daily devices we use, such as mobile phones and computers, to the aerospace field, batteries play a vital role. For electric vehicles, batteries are like its heart, responsible for delivering energy to the vehicle. So today, let's analyze the internal structure of the battery, see what the "heart" of the electric vehicle looks like, and where the price has increased.

We all know that the power of electric vehicles comes from a battery pack consisting of multiple interconnected modules, each of which is composed of dozens to hundreds of lithium-ion batteries, so let's study the internal structure and cost distribution of a single lithium-ion battery.

Lithium-ion battery refers to a secondary battery with lithium ions (symbol: Li+) embedded in compounds as positive and negative electrodes, which is what we often call a rechargeable battery. It mainly relies on the movement of lithium ions between the positive and negative electrodes to work. For example, when charging, Li+ is deintercalated from the positive electrode and embedded in the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; when discharging, the opposite is true, and this process is mainly completed through the following components.

First is the positive electrode, which is composed of positive electrode material + conductive agent + binder (PVDF) + current collector (aluminum foil). The positive and negative electrode materials must not only be active, but also have a very stable structure to achieve an orderly and controllable chemical reaction. At present, common positive electrode materials include lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, nickel cobalt manganese ternary materials, etc., and according to the different positive electrode materials, they can be divided into lithium cobalt oxide batteries, lithium iron phosphate batteries, lithium manganese oxide batteries, ternary lithium batteries, etc.

The negative electrode of lithium-ion batteries is made of a paste-like adhesive made of a negative electrode active material carbon material or non-carbon material, a binder and an additive, which is evenly applied on both sides of the copper foil, dried and rolled. The active material is required to be a good energy carrier, relatively stable, and have relatively abundant reserves to facilitate large-scale manufacturing.

There is also a layer of diaphragm between the positive and negative electrodes, which is generally 8 to 40 μm thick. In the battery system, it plays the role of separating the positive and negative electrodes, blocking the passage of electrons in the circuit during charging and discharging, and allowing the free passage of lithium ions in the electrolyte. It can selectively close the micropores when the battery is charging and discharging or the temperature rises to limit excessive current and prevent short circuits. The quality of its performance directly determines the overall performance of the battery. The diaphragms currently on the market mainly include single-layer PP, single-layer PE, double-layer PP/PE, and three-layer PP/PE/PP composite films.

Finally, there is the electrolyte, which plays the role of transmitting ions in the battery. It is mainly made of high-purity organic solvents, electrolyte lithium salts, and necessary additives, etc., prepared under certain conditions and in a certain proportion. The electrolyte allows lithium ions to have higher conductivity and improves the battery's charge and discharge efficiency, while its thermal stability has a great impact on the safety and cycle life of lithium-ion batteries.

After looking at the internal structure of the battery, let's talk about which part of the battery price has increased. Relevant data shows that the cost of a single lithium-ion battery mainly includes six aspects, from high to low, namely, the positive electrode accounts for 51%; the manufacturing process accounts for 24%; the negative electrode accounts for 12%; the separator, electrolyte and battery shell account for 7%, 4% and 3% respectively. We mentioned above that batteries can be classified according to the positive electrode material, mainly because the demand for metals that make up the positive electrode material is very large, which is also the reason why the cost of the positive electrode is so high.

At the same time, the latest data shows that the main raw materials for power batteries, such as lithium, cobalt, and nickel, have all risen sharply in price. Since December 21, 2021, the price of nickel has risen from less than 150,000 yuan/ton to 220,000 yuan/ton on March 20; the price of cobalt in the East China market has risen from less than 490,000 yuan/ton to 566,000 yuan/ton; the production price of lithium iron phosphate has risen from less than 100,000 yuan/ton to more than 150,000 yuan/ton, an increase of nearly 60%. So now everyone knows why the price of power batteries has risen.

Summarize:

If new energy vehicles want to develop further, constantly breaking through the technical bottleneck of batteries is a key, and there is still a long way to go. In addition, with the guidance of relevant policies and the stabilization of the new energy market, I believe that the prices of new energy should also stabilize in the future.