Low cobalt and cobalt-free are the development trend of battery cathode materials in the future. Talking about the future development of the battery industry, Feng Xuning, assistant professor and director of the Battery Safety Laboratory of Tsinghua University School of Vehicles and Transportation, pointed out. In this regard, Wu Fan, a doctoral supervisor at the Institute of Physics of the Chinese Academy of Sciences and the chief scientist of the Tianmu Lake Advanced Energy Storage Technology Research Institute, also expressed the same view: “For lithium-ion battery cathode materials,’high nickel and low cobalt’ or’no Cobaltization is the general trend.”
In the past 20 years, the semiconductor industry has developed by leaps and bounds. For example, the CPU process technology has always followed Moore’s Law, and performance can double every two years.
However, the battery technology has not made much breakthrough. Even though there are various “XX new battery” news rushed to the hot search every year, it is eventually reduced to a “PPT battery”: either because of the technical process or because of the cost. , Or because of various factors such as safety, it is difficult to get out of the laboratory, and it is difficult to mass produce and popularize on a large scale.
At the current stage, no matter how the new energy industry “should speak loudly”, batteries have always been a stumbling block in the development of electric vehicles.
Holding high the banner of “cobalt-free”, Musk enters the battery industry
With the official appearance of the 4680 battery on Tesla’s “Battery Day” in 2020, there is another “new player” in the battery industry, more precisely, a “spoiler”. According to Musk’s past “style”, every time he enters an industry, he will surely set off a bloody storm.
Batteries account for the bulk of the cost of the entire vehicle, so how to control the cost of Tesla’s battery production? This has to mention the important component in the battery-cobalt. This kind of metal with atomic number 27, located in the 4th cycle and group VIII of the periodic table of chemical elements, is an indispensable positive electrode raw material in battery manufacturing (at least it is still indispensable at this stage).
The battery industry consumes the largest amount of cobalt, accounting for more than 50%. Cobalt is an active substance, which can stabilize the layered structure of the material and reduce the mixing of cations, which facilitates the deep discharge of the material, thereby improving the discharge capacity, cycling and rate performance of the material; nickel can increase the activity of the material and increase the energy density. Wu Fan said.
In the natural ore, cobalt and nickel are in a symbiotic relationship, and its ratio is 1:10, that is, one part of cobalt is purified from the ore and ten parts of nickel can be obtained at the same time. “But cobalt has two shortcomings. First, cobalt has a certain degree of toxicity; second, it is more difficult to purify cobalt.” Feng Xuning said.
In addition, the lack of cobalt resources is also a disadvantage. “At present, the world has proven terrestrial cobalt resources of about 25 million tons and reserves of 7.2 million tons, mainly concentrated in the Congo (DRC), Australia and Cuba. The combined reserves of the three countries account for 68% of the world’s total reserves. Congo (DRC) reserves the highest first in the world, reaching 3.4 million tons. “Wu Fan pointed out,” cobalt because of its scarcity has become a rare strategic resource, while its centralized supply chain structure, unstable, has become the new energy vehicle development constraints. ”
low production + Difficulty in purification has caused the price of cobalt to continue to rise, which has also caused the cost of batteries to remain high. Can the battery be cobalt-free? The answer is yes.
Low cobalt or even no cobalt is not only the next route Tesla will take, but also a problem that needs to be overcome. Musk has also made it clear on the 2020 “Battery Day”. It is understood that as early as January 2019, Jeff Dahn (now the chief scientist of Tesla) published a paper pointing out the feasibility of “cobalt-free and high-nickel” cathode materials for lithium batteries. After all, nickel is more abundant in nature than cobalt. More, it is relatively easy to purify. Undoubtedly, it was Jeff Dahn’s views that greatly strengthened Musk’s confidence in building “cobalt-free batteries.”
Speaking of Jeff Dahn, Feng Xuning said: “With regard to lithium battery materials, especially cobalt-free materials, Mr. Dahn’s research group has carried out research very early. Mr. Jeff Dahn is one of the few scientists who have experienced the entire research and development of lithium battery technology and are still on the front line of technology. .”
The position of cobalt in the periodic table
Regarding the “cobalt-free” battery, Feng Xuning said: “‘Low cobalt’ and’cobalt-free’ are the future development trends of battery cathode materials. However, while the battery is “cobalt-free”, other ions must be added to replace cobalt in the battery The role of charging and discharging.”
Although Tesla’s batteries at this stage are still inseparable from cobalt, the cobalt content of its previous generations of batteries is continuously decreasing, and the final realization of batteries “cobalt-free” is just around the corner.
Forced to be helpless, Tesla is heading towards self-developed batteries
As the “big brother” in the field of new energy vehicles, Tesla knows the advantages of solid-state batteries and graphene batteries, but in the next few years, Tesla does not plan to do solid-state and graphene, but will continue to “deeply cultivate” lithium-ion batteries. The reason is mainly boiled down to two points.
First, it is subject to the supplier’s battery technology.
In terms of battery supply, Tesla has cooperated with Panasonic, LG Chem, and CATL. The 1865 batteries and 2170 batteries used by Tesla cars are provided by them, but they are subject to comprehensive factors such as performance, safety, scale, and price. In terms of trade-offs, cylindrical lithium-ion batteries are currently the best battery suppliers can give Tesla.
Obviously, there is still some gap between Tesla’s “ideal battery”. Since the battery supplier he wanted could not be provided, Tesla moved on to the road of “self-developed + self-produced” batteries.
The so-called “technical industry has specialization”, Tesla’s accumulation in the battery field is obviously not as good as Panasonic and other established suppliers, so it has spent a lot of money to invite the patriarch of the lithium-ion battery industry-Jeff Dahn to personally take charge as Tesla’s chief scientist Develop the “Impossible Triangle” battery, which is a lithium-ion battery with higher energy density, faster charging speed, and lower manufacturing cost.
Jeff Dahn did not humiliate his mission. After a year, he handed in an answer that satisfies Musk. Although the 4680 battery still has some shortcomings, its comprehensive performance has well boosted the confidence of the industry.
From third-party procurement, to joint ventures to build factories, to self-research and production, Tesla has taken its own steps on the road to batteries. It is foreseeable that in the next few years, Tesla will continue to use the multi-parallel scheme of cylindrical batteries along the existing mature route and continue to develop large-capacity lithium-ion batteries.
Second, Tesla’s business strategy.
In the final analysis, Tesla is a car company. If it is a company, it must be profitable. If it wants to be profitable, it must control costs. Although solid-state batteries are extremely superior, there are bottlenecks in both the technology and the process at this stage, and there is no possibility of large-scale mass production, and the cost is high, and there is no commercial practical value. In Tesla’s view, the use of mature lithium-ion batteries is a better solution at the moment.
The reason why Tesla pays so much attention to batteries is that in addition to affecting the performance of the vehicle, batteries account for as much as 40% of the cost of the vehicle. Only when the cost of the battery is reduced, can the cost of the vehicle be reduced. This is exactly why Musk announced on the “Battery Day” in 2020 that he would launch a US$25,000 (about 160,000 yuan) electric car within three years. The confidence comes from the fact that the cost of the 4680 battery has been reduced by 56%.
Tesla plans to launch a $25,000 electric car
Tesla’s business strategy is to “grab the market at low prices” to accelerate global market expansion. As Apple and other Internet giants have also announced that they will build cars, what Tesla has to do at this stage is to seize the market as soon as possible, relying on low prices. For consumers, price is still the top priority among many factors. For example, when Tesla announced a price cut before, the official website was paralyzed and offline stores were crowded.
Unlike some domestic new energy car companies who do “thousand-kilometer endurance” at any cost, Tesla pays more attention to the cost of batteries. Before the bottleneck of battery technology, and afterwards, there was a siege from major Internet companies. What the company wants to do most now is to reduce the price of electric vehicles as soon as possible, occupy the market at a lower price, and let the market quickly reach saturation.
Insiders: 4680 battery did not meet expectations
Regarding the Tesla 4680 battery, Wu Fan expressed his views: “Tesla mainly improves battery standardization production capacity by optimizing battery structural parts and simplifying battery production processes to achieve the purpose of reducing battery costs. This increase The technical route or idea of increasing the energy density of the battery pack by the volume of a single battery is essentially the same as BYD’s blade battery and the CTP technology of the Ningde era. ”
Too many batteries in parallel will cause adverse effects such as heat generation and low efficiency. , The large-capacity battery can effectively reduce the number of parallel connections, and the system management level becomes simpler. “High-capacity is the trend of the entire new energy vehicle battery industry.” Feng Xuning said.
Tesla Battery’s “Cobalt-Free High Nickel” Plan
Graphene battery technology is still under development
Looking at Tesla’s PPT introduction alone, the performance of the 4680 battery is really amazing, as if it once again gave the industry hope. However, in the eyes of industry insiders, this battery did not meet expectations.
”Tesla is a benchmarking company in the field of electric vehicles, and it will have a deeper understanding of batteries. Due to the high level of attention, the public has’high hopes’ for it, and industry insiders feel that the 4680 battery has not reached Expected.” Feng Xuning said. “It is undeniable that the overall performance of the Tesla 4680 battery is still ranked first in the world, but an attribution must be added in front of it-in the category of cylindrical lithium-ion batteries.” He then added.
Strictly speaking, the Tesla 4680 battery is more like an “optimization upgrade” rather than a “revolution.”
In addition, Tesla’s cylindrical lithium battery capacity also has a “ceiling.” “The main reason is that the cylindrical lithium battery needs a winding core, and the performance of the peripheral part is better. However, the closer the core position, the greater the curvature, and the phenomenon of stress concentration is prone to cause the active material to be unusable, thereby resulting in waste. So this battery capacity is If there is an upper limit, there is no way to make it particularly large.” Feng Xuning said. In the future, switching to other batteries, such as solid-state batteries that the industry is generally optimistic about, may be a better way out.
The current solid-state batteries and graphene batteries are actually in a transitional stage, that is, solid-state electrolytes and graphene are only “additives” in nature. “For example, adding solid electrolytes to lithium-ion batteries to increase energy density and improve safety; adding graphene to the negative electrode to enhance conductivity and increase charging speed. The more the two are added, the better the performance, but the corresponding process difficulty And the higher the manufacturing cost.” Feng Xuning said.
Obviously, whether it is a solid-state battery or a graphene battery, mass production is not possible at this stage.
Tesla’s triathlon: making batteries, fast charging, and building electric piles
The battery is directly related to the overall performance of the car, and the daily driving makes the car owner feel anxious, in addition to the cruising range, and then the charging speed.
Tesla battery recycling
”The cruising range corresponds to the energy density of the battery, and the charging speed corresponds to the power density of the battery.” Feng Xuning said, “If you want to increase the energy density, you can make the electrode thicker. If you want to increase the power density, you can make the electrode thinner. The two are contradictory, which requires battery manufacturers to comprehensively consider, make trade-offs and trade-offs in the process of designing batteries.” He added.
”Fast charging technology, battery manufacturers and car companies are each responsible for half.” Feng Xuning said. What the battery manufacturer can do is the “battery inherent” conductive ability, such as adding conductive agent, controlling the pre-tightening force of the cell, making the electrodes into gradient electrodes or thin electrodes, etc.; what car companies can do is “battery acquired” charging During the process, the current is controlled so that the battery is not overheated during charging and does not damage the electrode material. “Currently, the industry’s goal is to run 200 kilometers in 5 minutes on a charge,” he said.
Tesla’s fast charging technology is industry-leading. It uses a “high-power direct current” mode with a charging power of more than 40kW. For example, the Tesla Super Charging Station can charge half in 30 minutes and fully charge in 80 minutes. In terms of charging station/pile construction, Tesla is at the forefront of the world. According to statistics, Tesla has more than 20,000 super charging piles worldwide. There are more than 750 super charging stations and more than 6000 super charging piles in mainland China, covering more than 300 cities.
Regarding the pollution of waste batteries eliminated from electric vehicles. Feng Xuning said, “Waste batteries are pollution sources, which mainly refer to heavy metal pollution, such as lead in lead-acid batteries and cadmium in nickel-cadmium batteries. The raw materials inside lithium-ion batteries are less toxic (the proportion of cobalt in lithium-ion batteries is approximately 1% to 3%), generally will not cause heavy metal residues in the soil.”
Musk also publicly stated on the “Battery Day” in 2020: “Waste batteries can be recycled for use in low-profile vehicles or solar energy. In the field of energy storage demand, this can also further reduce the cost of battery use.”
In this regard, Feng Xuning said: “Battery recycling is generally divided into two categories, one is to continue to use under low load after being used up under high load, such as Some 5G communication base stations can use old batteries eliminated from electric vehicles; the other is directly scrapped, broken into raw materials through physical methods, and separated useful metals in the battery, such as copper, aluminum, cobalt, nickel, etc., and then sent back again The battery factory processes batteries, and the recycling efficiency in this respect is very high, close to 100%.”
At the same time, Wu Fan also pointed out some problems in the battery recycling industry at this stage: “First, there are many battery manufacturers and their use is scattered. Battery collection lacks effective channels; second, it is difficult to evaluate the remaining battery life and recycling price; third, battery disassembly is difficult, and there are certain safety risks; fourth, battery recycling involves many industries, and business models need to be further explored and improved. ”
From hardware development to software layout, Tesla is in the next big game
In the past, people’s cognition of traditional fuel vehicles only stayed at the “hardware” level, thinking that the car was just a means of transportation. In today’s era of new energy vehicles, people have discovered that the original car can also be equipped with an operating system and can be intelligent.
In the hardware of electric vehicles, the battery is undoubtedly the most core part; and in the software, fully automatic driving is the core. For example, Tesla’s FSD (Full Self-Driving) exists as a benchmark in the industry and charges fees. Not cheap. It is understood that the current price of Tesla FSD sets in China is as high as 64,000 yuan. “Tesla’s business layout and Apple will become more and more like the future, Tesla could become a service provider, do not rely solely on selling cars hardware, more profitable software and services.”
From From electric vehicle hardware to vehicle system software, from battery technology, vehicle assembly, to FSD and software ecology, it is not difficult to see that Tesla is making a big game.