Image source @ Visual China
Text | Wise driving
In 1993, China's first electric car turned out to be 8 hours on charge, which could drive 200km, and the car was built by Ye Wengui, the richest man in Wenzhou, Zhejiang Province, when Musk was only 22 years old.
Ye Wengui said, "This electric car can travel 200km on a single charge, with a maximum speed of 80 km/h. However, due to financial constraints, the electric car could not be commercialized and had to be discontinued in 1995. In the 2011 documentary "My Chinese Dream – The Story of Wenzhou, China," Ye Wengui muttered, "If you give me another 20 million, I will definitely let my electric car run on the highway." ”
Looking back now, in the 1990s, electric vehicles that could build a range of 200 kilometers were already considered to be the world's advanced level of endurance. Ye Wengui did not wait for the arrival of the electric era, which was convenient for his death in 2017. In the year of his death, the government began to introduce policies to encourage the support of electric vehicles. Four years later, new energy vehicles ushered in an explosive period, and the pure electric endurance exceeded 1000km.
From 200km to 1000km, China has been walking for nearly 30 years. At the beginning of 2021, the electric vehicle industry blew a wave of "1000km endurance". First, in January, WEILAI released ET7, with a range of 1000km. Immediately after that, in April, GAC Group released the "black technology" graphene battery, which also said that it could make the vehicle have a range of 1,000km.
In January 2022, Aion LX Plus was officially listed, the pure electric endurance reached 1000km, netizens praised the car mixedly, some said that the thousand mile endurance is really powerful, solving the endurance anxiety; some said that the premium of Aion LX Plus is too high, and the thousand mile endurance is not worth the price of 450,000.
Why is the price of thousand mile endurance so high? Why don't other car companies launch cars with a thousand mile range? In addition to increasing battery life, what other ways do we have to alleviate battery life anxiety? Today we will talk about the matter of thousand mile endurance.
01 How to achieve a 1000-mile endurance?
Back to the battery life pain points of the most concerned mobile phones, in the mobile phone life, want to achieve long battery life often only one condition, that is, to increase the battery volume, from the beginning of the Nokia era only a few hundred milliamps of batteries, the development of the current 5000mA or even more, the battery volume has been increasing, the size of the fuselage is also constantly getting larger.
But the car is not the same, at the beginning the power battery is indeed just a simple and rough increase in volume, but the body size is also so large in total, not to mention that most of them are still oil-to-electricity models, the space itself is small, want to increase the battery volume to achieve the purpose of expansion, can but there is an upper limit, this upper limit is subject to the body size, and blindly increasing the number of battery packs will also increase the weight of the car.
Obviously, this is not a path that can be developed, so what about not increasing the volume, but increasing the energy density of the battery? Theoretically feasible, but want to do this thing is extremely difficult, we have learned physics, battery energy density and battery capacity, platform voltage is proportional to the inverse ratio, and inversely proportional to weight. Among them, the battery capacity is determined by the gram capacity of the active material, so we can conclude that increasing the gram capacity of the active material can indirectly improve the energy density of the battery and improve the endurance.
Generally speaking, there are two ways to increase the gram capacity, one is to find new materials with higher theoretical gram capacity, and the other is to increase the gram capacity by changing the proportion of elements in the existing chemical system. These two ways are difficult, new materials are unattainable, it is likely that the existing resources of the earth can not find a replaceable material, graphene is a kind, but the progress is worrying, so most of the current car companies are using the second way, that is, to change the existing element ratio.
At present, the mainstream power battery is divided into ternary lithium and lithium iron phosphate, no matter which one, is very close to the upper limit of energy density. Among them, the cathode material of ternary lithium batteries is mainly composed of "nickel cobalt manganese". The nickel content directly determines the energy density, while the cobalt and manganese elements are responsible for the thermal stability of the battery, that is, safety.
Seeing this, everyone should also understand that as long as the nickel ratio of ternary lithium batteries is increased, the endurance performance can be further improved, but it will sacrifice thermal stability and safety. For example, the "811" battery in the Ningde era, from the name can be known, nickel elements accounted for 80%, while cobalt elements and manganese elements each accounted for 10%, 811 also got its name, 811 battery after the release, by users called it a time bomb, by consumers questioned.
At present, the "811" high-nickel ternary lithium battery has been quite popular, and the NEDC battery life can generally reach 500km or even more than 600km. If you want to further improve the endurance performance, you can only increase the content of nickel in the battery, which will undoubtedly bring huge safety risks. Therefore, the industry generally believes that 600km is a barrier for pure electric endurance.
Although lithium iron phosphate batteries are safe, the main focus of this battery is cost and safety, not endurance, and can only squeeze the last bit of potential through the new module process, which is the case for BYD blade batteries.
Changing the element ratio of the cathode material does not work, in order to make the electric vehicle endurance to achieve a qualitative leap, it is no longer possible to die of the cathode material, but to start from the part of the negative electrode material and the electrolyte. At present, several models with a range of 1000km have been released, which is exactly what is done, and the "sponge silicon anode sheet lithium battery" equipped with the AION LX PLUS 1000-mile edition is to achieve an increase in energy density through anode material innovation.
"Sponge silicon anode sheet" is to add silicon elements to the negative electrode material. Since the ability of silicon to store lithium ions is much higher than that of graphite, it can greatly improve the energy density of the battery. But the silicon element is not perfect, its biggest drawback is the form of instability, after multiple charge and discharge cycles can easily lead to the expansion or even rupture of the negative electrode material, resulting in battery energy density attenuation, simply put, it is not durable. As for how GAC chooses, it depends on the feedback of the owner after the delivery of the AION LX PLUS 1000 Mile Edition, and it is too early to say that GAC sacrificed durability to improve endurance.
02 Safety and cost are two big mountains
To put it simply, if you want to improve the endurance, it is nothing more than a material problem. So, why has only Aeon achieved mass production so far? Ouyang Minggao, an academician of the Chinese Academy of Sciences, once said: "If someone tells you that this car can run 1000km, can be fully charged in a few minutes, is still very safe, and the cost is still very low, this is impossible, don't believe it." The subtext of this sentence is: thousand-mile endurance is contrary to cost and safety.
If you look closely, you will find that in pure electric cars, the long-endurance version often sells better than the ordinary version, obviously everyone says to have long endurance, are worried about battery life anxiety, why to the stage of voting with RMB, and choose short endurance?
For example, GAC Aion LX Plus must be 450,000 top-of-the-line models to have a 1,000km endurance, while the low-end 600km endurance version only needs 280,000, a difference of nearly 200,000 before and after, the price of a BYD Tang dmi, have this money to buy two for a change to open the fragrance?
The price of new energy vehicles is not cheap, with an extra one or two hundred kilometers of endurance, the price is more than 100,000 higher, which exceeds the budget of many consumers. And the launch of the ultra-long endurance version of the model, from the current point of view, in addition to the mileage is a little longer, other car engine systems and the standard version of the model is not particularly different, for consumers, the attraction is obviously not enough, and it is not worth spending more than 100,000 yuan.
In other words, there is a problem of cost control. Not with a long battery life, is a long battery life means that the cost is higher, the price will be higher, and the consumer wants the long battery life, the premise is to do it at the same price, for example, a mobile phone is divided into 5000mA battery and 7000mA battery two versions, 7000mA that is more expensive than thousands, other configurations are the same, do not have to think about it to know that it must be 5000mA that sells better.
Of course, the thousand mile endurance is still the goal of the car company, the premise is that in the case of the price increase is not exaggerated, the civilian thousands of miles, is the real incense.
In addition to cost, the other side is security. In recent years, the safety accidents of new energy vehicles have shown an increasing trend, consumers not only have mileage anxiety, but also "safety anxiety", and power battery safety has become a roadblock to the development of the new energy automobile industry.
In October 2020, Hyundai announced a global recall of 51,000 KONA models due to a battery defect that caused a battery internal short circuit, coincidentally, BMW also announced a global recall of 26,700 vehicle models after three consecutive PEV fire accidents in October 2020, covering X1, X2, X3, X5, 2 series Active Tourer, 3 series, 5 series, 7 series, I8Coup and Roadster PHEV versions, as well as the Mini Countryman。 There are more and more safety hazards caused by battery safety worldwide.
In October 2021, LG paid GM up to $1.9 billion in damages for recalling and repairing Chevrolet Bolt electric vehicles due to two manufacturing defects in LG batteries, namely negative ear breaks and diaphragm folds, which put the vehicle at risk of spontaneous combustion. LG's high compensation incident has sounded the alarm bell for the entire industry, and it has become the consensus of the industry that battery companies have developed high-security batteries in order to further enhance market share and avoid high compensation in the later stage.
On the other hand, the national standard of safety has also been upgraded at the policy end, and the industry supervision has become more and more stringent. The new version of the "Safety Requirements for Power Batteries for Electric Vehicles" released on May 12, 2020 adds new battery thermal diffusion and overcurrent protection test items, in which the battery thermal diffusion test requires that after the battery unit is thermally out of control, the battery system must not have fire, explosion and other safety issues within 5 minutes, so as to reserve a safe escape time for the occupants.
At the same time, the "New Energy Automobile Industry Development Plan (2021-2035)" officially issued by the General Office of the State Council on November 2, 2020, compared with the draft for comments, added a description of "strengthening the quality and safety management, safety status monitoring and maintenance and maintenance testing of key systems such as vehicles and power batteries, electronic control", releasing the information on strengthening industry safety management and monitoring.
In this context, battery safety has become a new round of publicity points for car companies in addition to endurance and fast charging. Downstream new energy automobile enterprises are in a critical period of horse racing, safety accidents have serious damage to their brands, affecting their terminal market share, forcing car companies to attach importance to battery safety, and mainstream car companies have launched high-safety battery solutions. For example, BYD's blade battery has changed its strategy, and the main selling point is safety, not battery life. In this case, most car companies do not dare to sacrifice safety for the sake of endurance.
03 Super Boosters enter the acceleration race
Under the dual pressure of cost and safety, the popularity of thousand mile endurance still lacks preconditions, and if you want to eliminate mileage anxiety, you have to solve the problem from another angle. Compared with the slow progress of battery technology, fast charging, power exchange and other modes are the shortcuts to solve the anxiety of battery life in a short period of time.
Different from the thousand mile endurance, strengthening the construction of charging infrastructure and improving the charging experience is already the trend of the times in 2020. The "2020 Government Work Report" will include charging infrastructure in the "new infrastructure" and become one of the seven major industries; the "2020 Energy Work Guiding Opinions" point out that it is necessary to strengthen the construction of charging infrastructure and improve the charging guarantee capacity of new energy vehicles; and the "Guiding Opinions of the Ministry of Transport on Promoting New Infrastructure Construction in the Field of Transportation" clearly states that super fast charging and high-power charging vehicle charging facilities should be built in the highway service area.
So, how to do super fast charging? We all know that P (charging power) = U (charging voltage) I (charging current), so if you want to increase the charging power, there are no more than two ways, one is to increase the charging voltage, and the other is to increase the charging current. Among them, the fast charging scheme represented by Tesla is the high-current mode, while the high-voltage fast charging scheme represented by Porsche and so on.
From a technical point of view, Tesla as the representative of the large current mode, is indeed the optimal solution now, fast speed, low voltage, but the disadvantage is that the large current in the circuit will produce a high heat loss, this part of the loss is borne by the user, which is also one of the reasons why Tesla fast charging price is so expensive, its theoretical increase the upper limit is not high, so the platform architecture based on large voltage is an important technical path to solve the charging problem.
At present, the voltage platform of domestic hot-selling models also generally stays between 400-600V, such as bydirHan EV cruising range of 550km, the maximum charging system voltage of 569.6V, can achieve 25 minutes 30%-80% SOC charging speed. However, the charging speed of half an hour may be further broken in 2022, when the energy supplement of new energy vehicles can basically be comparable to fuel vehicles.
The reason why I dare to say that it is comparable to fuel vehicles is because in 2021, the energy storage industry has a key word, that is, 800V high-voltage fast charging, according to the "2021-2022 800V high-voltage platform research report" of Zosz Auto Research Institute, in 2021 BYD, Geely, Great Wall, Xiaopeng, Ideal, Zero Run and so on have successively released the layout plan of 800V high-voltage technology.
A study by Huawei shows that fast charging using 800V high-voltage mode supports 30%-80% SOC maximum power charging, while low-voltage high-current mode can only charge maximum power at 10%-20%SOC, and the charging power drops very rapidly in other ranges.
It can be seen that the 800V high voltage mode can support longer fast charging. Huawei has given a set of clear technical goals: by 2025, it will launch a fast charging solution with a voltage platform of more than 1000V and a power of 600kW, which can achieve 30%-80% SOC charging performance in 5 minutes, which is very close to the speed of refueling.
At the supply chain end, high-voltage technology has been initially completed, related components are expected to start mass production in the industry in 2022, such as ZF said that it will mass-produce 800V power electronics in Central Europe in 2021, Huawei, BorgWarner, Huichuan Technology, etc. have successively released 800V electric drive systems, on the high-voltage fast charging technology has achieved a breakthrough from 0 to 1, followed by gradual scale expansion and downward penetration, waiting for them is the further reduction of costs, need to rely on large-scale mass production and application.
In addition to high-voltage fast charging, another way to quickly replenish the power is to replace the power, on January 18, 2022, the Ningde era released the EVOGO power exchange brand, the main content includes the power exchange block, the power station and app supporting services three pieces of content. Among them, a single power exchange block can provide about 200km of endurance, the power exchange time is 1 minute, Ningde power exchange will face all car companies, which is another major action of Ningde in the field of power exchange, but also shows that the power exchange mode has gradually become the consensus of the industry.
In addition, Sinopec, a big man in the oil field, also proposed in 2021 to build a target of 5,000 charging and replacing power stations, so as to officially enter the power exchange service. By December last year, Sinopec had cooperated with Weilai, Aodong, Geely and other companies to build 65 substations, and at the same time strengthen research and development to jointly promote the landing of general-purpose substations.
Following Weilai, Xiaopeng Automobile has also established new companies in Guangzhou, Jiaxing, Shenzhen and other places, and its business scope includes car power exchange. Dongfeng, BAIC, Changan, SAIC, Geely, Yutong Bus, Guojin Automobile, China Southern Power Grid and other related enterprises have also said that they will actively layout the research and development and promotion of the power exchange model.
If the early replacement power station is tepid, it is due to battery-related technology, lack of standards for equipment, the ownership of new energy vehicles is very low and other factors, and now, with the policy turning again to support power exchange, battery technology, equipment, etc. tends to be standardized, the business model is mature, the power exchange technology is constantly iterative, and more importantly, the new energy vehicle shows explosive growth, so that the power exchange has the prerequisites for vigorous development again, and also brings new growth space and development opportunities to the entire industrial chain.
04 Write at the end
Judging from the actions of the above car companies and energy storage industry, the high-voltage fast charging and power exchange mode is the optimal solution to solve the endurance anxiety at present, and it is also the fastest approach. So, is there still a place for thousands of miles of endurance in the future?
There is no doubt that there are, but it may not be now, after all, there are too many preconditions for thousand mile endurance, safety, cost and other factors, so that thousand mile endurance is still a small number of players show technology, to achieve civilian thousands of miles, there is still a long way to go. Looking back at 1993, Ye Wengui built a 200km endurance electric vehicle, the era is not ready to meet the arrival of electric vehicles, the foresight of technology is vulnerable in the face of the limitations of the times, the landing of any revolutionary technology needs to be coordinated by the environment, thousands of miles of endurance, and finally lead the market or short-lived, time will tell us.