Text/Peach Lee
With the steady development of the new energy market and the continuous improvement of the penetration rate of new energy vehicles in the market, many car companies have also begun to put the plan of gradually stopping production of fuel vehicles on the agenda, and have changed their development focus to the direction of pure electric. However, from the current market situation, the development of new energy vehicles seems to have entered a bottleneck period, first of all, the problem of endurance anxiety has not been solved; secondly, with the growth of market demand, the upstream raw material industry of new energy has increased prices. And these problems all point to one place, that is, the batteries of electric vehicles.
When it comes to batteries, we are not unfamiliar, from the daily devices we use, such as mobile phones, computers, etc., to the aerospace field, batteries play a vital role. For electric vehicles, the battery is like its heart, bearing the role of transmitting energy to the vehicle, so today I will take you to dissect the internal structure of the battery to see what the "heart" of the electric vehicle looks like, and where the price increase is.
We all know that electric vehicles are powered by battery packs composed of multiple interconnected modules, each of which is composed of dozens to hundreds of lithium-ion batteries, so we will study its internal structure and cost distribution from a single lithium-ion battery.
Lithium-ion battery refers to a secondary battery with lithium ions (symbol Li+) embedded compounds as positive and negative electrodes, which is what we often call rechargeable batteries. It mainly relies on lithium ions moving between the positive and negative electrodes to work, for example, when charging, Li+ is de-embedded from the positive electrode, and the negative electrode is in a lithium-rich state through the electrolyte embedded in the negative electrode; the opposite is true when discharging, and this process is mainly done through the following components.
The first is the cathode, which is composed of a cathode material + conductive agent + binder (PVDF) + fluid collection (aluminum foil), the positive and negative electrode materials must not only be active, but also have a very stable structure to achieve an orderly, controllable chemical reaction. At present, the common cathode materials are lithium cobalt oxide, lithium iron phosphate, lithium manganate, nickel cobalt manganese ternary and other materials, and according to the different cathode materials can be divided into lithium cobalt oxide batteries, lithium iron phosphate batteries, lithium manganese oxide batteries, ternary lithium batteries and the like.
The negative electrode of the lithium-ion battery is made of a mixture of carbon or non-carbon materials, adhesives and additives of the negative active substance carbon material, adhesive and additives evenly applied on both sides of the copper foil, dried and rolled. The active substance is required to be a good energy carrier, but also relatively stable, but also has relatively rich reserves to facilitate large-scale manufacturing.
There is also a layer of diaphragm between the positive and negative electrodes, the thickness is generally 8 ~ 40μm, in the battery system plays a role in separating the positive and negative poles, blocking the electronic passage in the circuit when charging and discharging, allowing the free passage of lithium ions in the electrolyte, and can selectively close the micropores in the case of battery charge and discharge or temperature increase to limit excessive current and prevent short circuits, and the advantages and disadvantages of its performance directly determine the overall performance of the battery. At present, the diaphragms on the market mainly include single-layer PP, single-layer PE, double-layer PP/PE, three-layer PP/PE/PP composite film, etc.
Finally, the electrolyte, which plays a role in transporting ions in the battery, is mainly composed of high-purity organic solvents, electrolyte lithium salts, and necessary additives and other raw materials, under certain conditions, according to a certain proportion of the preparation. The electrolyte allows lithium ions to have higher conductivity, improve the charge and discharge efficiency of the battery, and 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 increase. Relevant data show that the cost of a single lithium-ion battery mainly includes six aspects, from high to low, the positive electrode accounts for 51%; the manufacturing process accounts for 24%; the negative electrode accounts for 12%; the separator, electrolyte and battery housing account for 7%, 4% and 3% respectively. As we mentioned above, batteries can be classified according to the cathode material, mainly because the metal that makes up the cathode material is very large, which is why the cost of the cathode is so high.
At the same time, the latest data show that the main raw materials of lithium, cobalt, nickel and other power batteries have risen sharply. Since December 21, 2021, the quotation of nickel has risen from less than 150,000 yuan / ton to 220,000 yuan / ton on March 20; the quotation 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 all the way to more than 150,000 yuan / ton, an increase of nearly 60%. So now everyone knows what the reason for the price increase of power batteries is.
summary:
New energy vehicles want to further develop, and constantly break through the technical bottleneck of the battery is a key, which still has 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 price of follow-up new energy should also be stable.