What can we interpret from Tesla?

　　Author ：Iflowpower – Portable Power Station Supplier

If you pay attention to Tesla, you must know that it is brewing, it is to replace the 18760 battery that is being used as a 2170 battery. The first model with a new battery is MODEL3. It is reported that Models and Model are also expected to replace them.

And the important use of the 2170 battery will also be energy products such as PowerWall2 and PowerPack2. In fact, on the CES (International Consumer Electronics Product Exhibition) held in January this year, the 2170 battery has been. Tesla announced that this battery will be produced in GigaFactory Super Battery Factory, the annual output of 35GWh / year, almost with the world's battery production is quite.

Most people think that this is the symbol of Tesla further enhances the product. However, after the excitement, I realized that this matter didn't think so simple. What is 18650/2170? Let's first understand what these boring models represent.

18650 naming method: a diameter of 18mm, length 65mm, "0" represents cylindrical. This is very similar to the traditional No. 3 battery (17500: a diameter of 17mm, length 50mm).

In addition to electric vehicles, 18650 batteries are mostly used in laptops and glare flashlights. The same truth, 2170 representative: 21mm diameter, length 70mm. There is no "0" 2170, which is the unique name of Tesla, but also means a cylindrical battery.

The above two batteries are both Tesla and Panasonic cooperation products. Although the size becomes large, you can see Tesla still use the ternary lithium ion battery mode. Previously, Tesla Battery Director Kurtkelty's evaluation of this type of battery is: more energy density, better consistency; effective reducing the cost of battery systems; small size but controllability and security are constantly improve.

What does the size mean? Elonmusk said that "the energy density of the 2170 battery is the highest in the world, and will be the cheapest. "The original 18650 battery is limited by volume, and the process is very mature, and the energy density improvement is from the perspective of the process control, and there is no breakthrough progress. And considering cost reasons, increase the volume is more sensible.

Tesla proposed, the energy density of the 2170 battery system currently produced is around 300Wh / kg, and the battery system is 250Wh / kg, and it is increased by 20%. Energy density improvement rate is considerable. In addition, as the cell monomer is increased, the internal resistance is small, and the charge and discharge will become smoother.

The use of a large number of small batteries is connected to the flexibility and anti-defense, but use small cylindrical battery packs in a full-size electric vehicle, which means that thousands of large currents are connected, and each joint is It is the potential source of overheating. Placed in Tesla, representing more than 7,000 potential overheat existence. Although Tesla is full of hard work in battery safety technology such as battery, pack, battery management system, but does not worry.

This time, the battery volume increases, the number of joints is reduced, and the source of overheated is reduced accordingly. Tesla official is very confident in this new technology price advantage, proposing: 2170 battery system cost is $ 155 / WH (18650 type 171 US dollar / Wh); expected price of $ 170 / WH (18650 price 185 USD / WH). However, from the construction progress of the GigaFactory plant, the 2170 battery is in the early current cost advantage.

Is the three yuan lithium ion battery safety? This is a topic of an old bonus, but in Tesla, it is still a brief introduction. If the three-dimensional lithium ion battery is internally short-circuited or the positive material, there will be a risks of fire. At the beginning of 2016, the three-yuan lithium-ion battery bus included in the new energy vehicle promotion application recommended models, and therefore it was once called by the Ministry of Industry and Information Technology.

In response to this problem, Tesla uses steel shell to protect the 18650 battery. The thermal stability of the three-dimensional lithium material is also poor, and it will be decomposed around 200 degrees, and chemical reflections are intense, and the oxygen molecule will be released, and there is a chain reaction risk. The decomposition temperature of lithium iron phosphate will be higher than three times (700-800 degrees), and oxygen molecules will not release oxygen.

Due to the stability of the three-dimensional lithium-ion battery, there will be a risks of fire when it is seriously collided. It is also this reason. The previous electric passenger car basically has a stable safety performance, and the high temperature is better lithium iron phosphate ion battery.

The automotive collision safety requirements of the three-dimensional lithium ion battery will be higher. Tesla is doing well in this regard. For example, in 2014, Tesla Models was the only one in the same year, while obtaining the five-star safety certification model issued by Euro-NCAP and NHTSA.

This is benefited from the use of Tesla's body design (all-aluminum alloy body and high-strength boron steel strengthening structure), battery structure layout (battery pack is located directly below the chassis) and the active safety technology (under driver technology Auxiliary technology). Although Tesla still has a safety accident, the safety of this method is still trustworthy. It should be noted that the three-dimensional lithium-ion battery safety problems still exist.

Tesra Dare to adhere to this technology, from Tesla in improving battery safety technology, also studied a lot of research on traditional body safety technology. In other words, Tesla told us that this technology has a good rising space, but this does not represent anyone who uses this technology. Tesla's insistence will drive the expansion of the three-yuan lithium-ion battery under policy driver.

At present, the new energy vehicle market structure is undergoing changes, new energy passenger cars, and new energy special car proportion gradually improved. At the end of 2016, the three-yuan lithium-ion battery storm announced the "Notice on Further Working on Further Good New Energy Automobile Promotion and Application Safety Supervision", which also means that the three-yuan lithium-ion battery will return to the public vision on the electric passenger car. Electric passenger car Overlord BYD, before the insistence on the phosphate ion battery, it is observed.

However, at the end of the same year, he changed the normal state. Manganese "three-dimensional lithium ion battery. Inadvertently, Beiqi Xin Energy also abandoned lithium iron phosphate route in 2015.

The two electric vehicles listed in the year were three yuan lithium ion batteries. As the industry benchmark, Tesla will undoubtedly it will be a deputy pill. Tesla, this choice is undoubtedly wise to himself, which also verifies Kurtkelty for the view and expectations of this technology.

Tesla with higher energy density will inevitably improve battery life and explosive power. Previously, as an emerging company, there was quite a big tribute, and now it be more robust to mature. There is rising in steady, this is the impression of Tesla.

Sany-lithium-ion battery technology is under Tesla's boost, I believe there will be better development. But we don't have the success of Intrisla, simply confirming the safety and reliability of the ternary lithium-ion battery. Although the three-yuan lithium ion battery has many possibilities, we can't ignore a series of safety measures made by Testra, but no one has learned.