Is Tesla's cobalt-free battery a scam?
August 28, 2020
Is Tesla's cobalt-free battery a scam?
Some time ago, Tesla publicized its preparation to go the cobalt-free route. As a star traffic company, Tesla's move has had a great impact on the market. However, this does not seem to be the case. On June 16, news broke that Tesla purchased cobalt from Glencore, and the transaction volume may be as high as 6,000 tons per year.
Tesla has previously used ternary batteries (NCA) supplied by Panasonic, which contain cobalt. For this reason, in the Tesla earnings call last year, some analysts mentioned to Musk the price of rare metal commodities such as cobalt. The drastic changes will affect Tesla's prospects. Musk's response to this was: the use of cobalt can be reduced to zero. Since then, Tesla will introduce the concept of cobalt-free batteries.
Is it feasible to go to cobalt for ternary batteries?
In May 2019, Tesla announced the completion of the acquisition of Maxwell. Maxwell is a world-renowned manufacturer of supercapacitors. Tesla’s acquisition of Maxwell did not want to replace lithium-ion batteries with supercapacitors, but rather focused on the production of supercapacitors. Method technology. A senior industry expert told a reporter from my country Automobile News that compared to traditional lithium-ion battery production methods, using dry electrode technology has many advantages.
On February 3, CATL announced that the company intends to sign agreements with Tesla and Tesla (Shanghai) Co., Ltd. According to the agreement, CATL will supply lithium-ion power lithium battery products to Tesla. There have been rumors that CATL will supply lithium iron phosphate batteries to Tesla. Lithium iron phosphate batteries do not contain cobalt. Some people naturally associate the concept of using lithium iron phosphate batteries with cobalt-free batteries in the Model 3 of Tesla's Shanghai plant.
Supercapacitors do not contain cobalt, and lithium iron phosphate batteries do not contain cobalt. After the concept of cobalt-free batteries was launched, after a period of hype, the concept seems to have been strengthened. According to the information of Jintou.com, on May 05, 2019, electrolytic cobalt ge was 99.8%, and the price was 263,000-278,000 yuan/ton. On May 20, 2020, electrolytic cobalt ge was 99.8%, and the price was 245,000 yuan/ton. In about a year, the price of cobalt dropped by 18,000-33,000 yuan/ton.
If estimated according to the annual transaction volume of 6,000 tons between Tesla and Glencore, Tesla can save about US$15-28 million (equivalent to RMB 1.08-198 million). Tesla and Glencore did not disclose the details of the agreement, and the agreed price of the two parties has not been announced to the outside world. We can only calculate it based on public information. In short, after the price of cobalt drops, Tesla can save a lot of money to buy cobalt metal.
Is it feasible to remove cobalt from ternary batteries? An expert once said in an interview that theoretically, cobalt-free ternary materials can be achieved. After cobalt-free, the composition of the material will change greatly, and the cathode material may become a binary or quaternary material, but the basic structure remains unchanged. The binary material refers to lithium nickel manganese oxide, and the quaternary material refers to nickel cobalt manganese aluminum (NCMA) polymer.
In an interview, Mo Ke, President of True Lithium Research, believes that the ternary removal of cobalt is not yet practical, and battery giants such as Panasonic and LG Chem are still unable to achieve practical use of cobalt.
When Tesla announced the completion of the acquisition of Maxwell, the reporter interviewed many experts in the industry. Chen Shengjun, chairman of the Super Capacitor Industry Alliance and general manager of CRRC New Energy, told reporters that super capacitors are not restricted by precious metal resources such as lithium, cobalt, and nickel. The important raw material is activated carbon, which is mainly derived from natural biomass such as coconut shell. Activation made.
Acquired Maxwell for dry process technology
Tesla's acquisition of Maxwell took a fancy to the dry process technology. Chen Shengjun said: The dry process can significantly increase the load of the pole piece active material, thereby effectively increasing the energy density of energy storage devices. According to Tesla's evaluation, if the process is applied to lithium-ion batteries, the energy density of lithium-ion batteries can be increased by more than 10%-30% under the existing system conditions.
During the charging and discharging process of lithium-ion batteries, the lithium ions extracted from the positive electrode do not return to the positive electrode 100% during discharge. If a lithium source can be found outside the positive electrode material, the lithium ions extracted from the positive electrode will not be wasted. In the formation process, the full battery capacity can be increased in the end. This process of supplying external lithium source is prelithiation. Pre-lithiation is of great significance for improving the energy density and cycle life of power lithium batteries. Traditional wet process uses a large amount of organic solvents, and it is difficult to achieve prelithiation. In the dry process, no solvent is involved in the entire preparation process, so metallic lithium can be added during the raw material mixing stage.
Dry technology has many benefits, not only to improve the performance of lithium-ion batteries, but also to significantly reduce costs. Compared with the traditional process, the dry process technology eliminates the solvent addition, drying and evaporation, and secondary rolling in the coating process, and the cost is naturally greatly reduced. In addition, after the electrode is cut and separated, it is not coated with the current collector The material can still be rolled again. The traditional wet method cannot be reused in this way.
In the production process, the assembly line must fiberize PTFE (polytetrafluoroethylene), so that the active material and the fiberized PTFE (polytetrafluoroethylene) form a network cross-linked structure, which is one of the difficulties of pretreatment before film formation. In the continuous extrusion and rolling process, the pretreated active material is still a powder material, so that the powder material can form a uniform sheet material, which is still another difficulty in the entire process.
The formed sheet material must have high mechanical strength. Only in this way can the continuous production of the entire process flow be ensured. The sheet material must also have a bright surface to ensure uniformity and consistency.
The lithium-ion battery project launched by Tesla is already on the line, and it has to be announced. The lithium-ion battery project launched by Tesla is not lithium iron phosphate. It was reported earlier that it was a ternary battery. However, time waits for no one. Tesla cannot wait until a real breakthrough in dry technology to produce lithium-ion batteries. Ordering cobalt early can ensure that it will not be in a passive position in the future.