It's all big movies. Three speculations about Tesla battery day.

Power battery is the heart of electric vehicle. Cost, energy density, cobalt supply, etc. It has always been an important topic for the industry to seek technological breakthroughs. Tesla, which has mastered the core technology of Sanpower, as a global leader in electric vehicles, has been planning the layout of batteries for a long time, and now it is approaching the moment of flowering and fruition.

Tesla holds a theme day every year to reveal the latest strategies and technologies and predict the future development direction of the company. In the third week of May, the long-awaited battery day (battery? Day) is coming, which is a day to decide the future of Tesla and even the electric vehicle industry chain. How many blockbusters has Musk prepared? According to the clue, EV Vision speculated that there were three.

1 million miles! A great leap in battery life

In April last year, at Autonomy Day, when talking about the economic benefits of robotic taxis of Tesla's self-driving fleet, Elon Musk emphasized that such vehicles must be durable. Tesla Model 3 can travel 654.38+0.6 million kilometers like a commercial truck, but its cruising range is between 480,000 kilometers and 800,000 kilometers.

Musk claimed at the time that Tesla would launch a new battery in 2020, and its life span would reach the goal of 1.6 million kilometers.

To this end, Tesla and Dalhousie University in Canada reached a five-year research partnership agreement five years ago to develop advanced lithium-ion battery technology.

Led by physicist Jeff Dahn, one of the most outstanding lithium ion researchers in the world, the research and test results recently released by Dalhousie's research team show that they have designed a battery with a battery life of 654.38+0.6 million kilometers.

This new battery is still a lithium battery. The new battery mainly relies on single crystal nickel metal hydride (NMC), artificial graphite battery technology and electrolyte additive ODTO to improve the performance and life of the battery and reduce the cost. Among them, the negative electrode of the battery is mainly lithium, and the nanostructure is composed of large NMC crystals, which are not easy to break due to continuous expansion and contraction during charging and discharging, otherwise the performance of the battery is easy to decline. This is two to three times more durable than Tesla's current battery.

Dalhousie's research team has done a variety of battery performance tests under different conditions and cycles, including long-term charge-discharge cycles at 20 C, 40 C and 55 C, long-term storage at 20 C, 40 C and 55 C, and high-precision power analysis at 40 C.

After 4000 charge and discharge cycles, the capacity of the new battery still remains an astonishing 90%. In a wide temperature range, the number of charge and discharge cycles can be increased to more than 6000 times. This means that a good battery pack can easily exceed 6.5438+0.6 million kilometers. If it is used in battery grid energy storage technology, it can also be used for more than 20 years.

This longevity potential is obviously particularly useful for all-weather electric vehicles. At present, Dalhousie research group has applied for a patent. If the research and development is successful in the future, it will not only help ordinary electric vehicles, but also benefit heavy-duty long-distance trucks and self-driving taxis.

New research also confirms that Tesla will gradually get rid of its dependence on battery supply such as Panasonic in the future.

Reduce the cost to 100 USD.

In February this year, Tesla's secret project named Roadrunner flowed out, aiming at mass production of cheaper batteries with the strategy of "manufacturing machines", that is, manufacturing equipment by itself, with the goal of reducing the battery cost to 65,438+000 USD/kWh.

From developing 18650 lithium cobaltate, to finding another way to NCA ternary lithium, and then to "no cobalt, it doesn't mean it must be lithium ferrous phosphate." According to industry analysis, Tesla's cost reduction scheme may be a combination of high nickel anode+silicon carbon cathode (doped with lithium)+dry electrode+supercapacitor.

In order to reduce the cost, cobalt removal is inevitable. Nickel is similar in nature to cobalt, but its price is only one fifth of that of cobalt. In ternary lithium batteries, increasing the cobalt-nickel ratio can improve the energy density, but the high nickel anode will reduce the thermal stability, and the dry electrode can solve this problem. Silicon-carbon cathode can improve the capacity of lithium ion, ensure that the cathode does not become a bottleneck, and the supercapacitor can recover kinetic energy.

In the past few years, Tesla has been ready for this new technology combination. In 20 19, Maxwell, the manufacturer of supercapacitors, was acquired for the first time, with battery technology.

Maxwell's core technologies are supercapacitors and dry electrodes, which enable Tesla to manufacture batteries at lower cost and higher energy density, reduce the number of batteries used in each car, but still get a longer cruising range.

Maxwell dry electrode technology makes the anode and cathode of the battery use adhesive and conductive agent instead of solvent, thus overcoming the problem of poor thermal stability of high nickel electrode of ternary lithium battery. The energy density can reach 300Wh/kg, and may even exceed 500Wh/kg in the future.

The energy density of 2 170 battery of Model 3 is 247 Wh/kg, and that of 18650 battery of Model S/X is 240 Wh/kg. If the mass production can reach 300 Wh/kg, it will increase by more than 20%, that is to say, the NEDC cruising range of the long-life Model 3 can reach 800km, which is a major progress in chemical technology and production technology.

In addition, dry electrode technology can also extend the life of lithium batteries by about 1 time. There is no need to use solvents and related expensive equipment, which greatly saves the manufacturing cost. Generally speaking, dry electrode technology can reduce the battery cost 10% to more than 20%. Supercapacitors can also recover the wasted energy during the acceleration, deceleration and start-stop of automobiles, and can be used in conjunction with lithium batteries to improve energy efficiency.

The road to self-produced batteries

Tesla's sales are currently mainly restricted by battery capacity.

At the shareholders' meeting of 20 19, Drew Baglino, vice president of Tesla technology, expressed the hope that Tesla would become "the master of its own destiny" in the field of batteries.

In 20 19, Tesla acquired Hibar Systems, a Canadian manufacturer of lithium battery equipment, which is a leading company in the field of battery manufacturing equipment and is famous for its precision metering pumps, liquid injection systems and battery manufacturing systems, especially for large-scale electric energy storage.

The acquisition of Bahai is seen as Tesla paving the way for independent production of batteries.

In February, 2020, a recruitment message suggested that Tesla would build a trial battery production line in fremont, California, and independently design, develop and manufacture batteries. On May 6, the Korea Times reported that Tesla had signed an order for battery formation equipment with Hanwha Group of Korea, and the purchased lithium battery equipment would be first applied to this trial production line. In addition, the electromagnetic filter was purchased from dae bo Magnetic. According to sources, except for several aspects of the battery production line, Tesla can manufacture almost all engineering equipment, and the equipment supply has been prepared since a year ago.

"The machine that makes the machine", the self-sufficiency of the battery fully conforms to the first principle mentioned by Musk. It is understood that Tesla is preparing to build the next generation super factory Terafactroy in Texas or an eastern state. The battery capacity may exceed 65,438+0 TWh, that is, 65,438+000 GWh, which will be 20 times that of Gigafactory in Nevada.

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The battery life is 654.38+0.6 million kilometers, and the cost is as low as 654.38+000 USD/kWh, which reduces the dependence on self-developed and self-produced batteries ... Battery Day may be Tesla's most important technology and strategy announcement in recent years. If Musk really releases a few big breakthroughs, Tesla's lead will be several blocks behind others.

This article comes from car home, the author of the car manufacturer, and does not represent car home's position.