Six or seven years ago, the first wave of domestic consumers had just begun to come into contact with new energy vehicles, and their focus was only on whether they were reliable and how long they could be driven. Two or three years later, policies began to tilt toward new energy vehicles, and new power brands sprung up like bamboo shoots. Of course, traditional car companies were not to be outdone. With the surge in the number of new energy vehicles, a series of problems such as subsidy fraud and false marking have also begun to emerge. However, at that time, most people did not pay much attention to vehicle technology, and their attention was still focused on battery life and energy replenishment. At the same time, the range of the first wave of electric vehicles began to shrink severely, and safety and reliability issues gradually emerged. It was also at that point that manufacturers and consumers truly began to face up to the importance of new energy technology to the long-term development of the industry.
Now the new energy vehicle market has completed the cleanup of "cheating and abduction", and the surviving manufacturers have their own Technology has accumulated, and the industry’s technical routes and development trends have also taken direction. Looking back at 2021, which is about to end, there are many new technologies and many product iterations, but they are basically focused on three aspects: solving battery life anxiety, improving the reliability of new energy vehicles, and implementing future technologies, so today we will review them together. What achievements have each new energy vehicle company made in the past year?
The original sin that makes many people reject electric vehicles in the first place is battery life anxiety. To put it simply, the root of the problem in colloquial terms is nothing more than small battery capacity, slow charging speed, and safety is a question mark. In response to these problems, different manufacturers have given different solutions.
BYD
As one of the first domestic car companies to get involved in new energy vehicles, BYD is far from as simple as everyone thinks. Because car manufacturing is only one of its many business departments, and it is involved in light and heavy industries such as the research and development of battery electronic control technology, electronic product foundry, buses, Yunnan Railway, the research and development and manufacturing of heavy machinery, etc.
The most eye-catching move by BYD this year is that blade batteries have begun to be installed in large quantities in vehicles. In fact, BYD's blade batteries have been released at the end of March 2020. What makes them famous is not the increase in energy density or cruising range.It is the daunting "needle prick test" of the battery circle (and power battery thermal runaway/safety test). The acupuncture test uses a 5mm diameter steel needle to pierce the battery pack to check whether the battery pack will spontaneously ignite. After the blade battery is pierced, the battery temperature is maintained at 30-60 degrees, and there is no open flame, no smoke, and no burning. This phenomenon proves that it has a high degree of safety and can also bring consumers a sense of security and trust for daily use.
At the technical level, BYD’s The blade battery uses lithium iron phosphate material as the battery core. Lithium iron phosphate has the advantages of high exothermic starting temperature, slow heat release, low heat production, the material does not release oxygen during the decomposition process, and is not easy to catch fire. In addition, the blade battery also has refrigerant direct cooling technology for temperature control, and is heated through high-frequency discharge, which is less affected by the ambient temperature. In terms of shape, the single body shape is long and flat, with a thickness of less than 2 cm. The structural layout adopts a matrix arrangement, which also has advantages in stiffness and strength. Compared with traditional ternary lithium batteries, not only the structure and safety have been enhanced, but the higher volume utilization also makes up for the disadvantage of lithium iron phosphate in energy density to a certain extent.
Then there is the DM-i hybrid system, which is popular among consumers as production capacity exceeds supply. BYD's hybrid technology has now gone through three generations. The first-generation DM dual-mode system realizes a half-oil and half-electric hybrid mode by connecting two motors in series and parallel. The quality is good when there is electricity, but it is relatively useless when there is no electricity. The second-generation DM technology focuses on the power performance of the motor and is based on the P3+P4 architecture. That is, the motors are placed behind the gearbox and on the front and rear axles respectively, and work together through signal coordination. Although the performance of pure electric battery life has been enhanced, the driving quality and fuel economy performance are still poor under the condition of power loss. The third generation DM technology adds a BSG motor to the second generation, which optimizes fuel economy and quietness to a certain extent, but the starting point is still to give priority to power. The new fourth-generation DM-i technology splits the product line into DM-P and DM-i. DM-P technology ideas tend to be third-generation technology, while DM-i uses a dual-motor string of large motor + large battery. The parallel connection method achieves excellent fuel economy performance.
To put it simply, the DM-i hybrid system consists of an Atkinson cycle engine with ultra-high thermal efficiency, a generator and a drive motor. It consists of EHS electric hybrid system, blade battery, DC AC car charger and other components. The gearbox part has also been replaced by a set of single-speed reducer, which not only has higher transmission efficiency, but also has smoother performance more like an electric vehicle. In addition, due to the use of BYD's fourth-generation IGBT technology, the overall efficiency of electronic control has also reached a new height, and 2C or even higher level fast charging can be achieved in the charging process.
LongCity
In most people’s minds, Great Wall Motors It has been developing traditional fuel vehicles, and the most famous ones are of course the Haval H6, Cannon, and Weipai Tank 300. After all, the H6, which has hundreds of configurations, sells more than 30,000 yuan per month all year round. The appearance of the gun has subverted the perception of independent pickup trucks, and the hard-to-find Tank 300 has become a value-preserving and price-increasing artifact.
However, while focusing on fuel vehicles, Great Wall has not slowed down the pace of research and development in other technology lines. Zi’s hydrogen lemon platform, lemon DHT hybrid, etc. have also been launched one by one this year. Among them, the Lime platform can be regarded as another technical route besides fuel, hybrid and pure electric. Although the probability of civilian application is low, the commercialization aspect has been revealed. We all know that commercial vehicles are both large carbon producers and energy consumers. However, the entire process from processing to use of hydrogen fuel involves very little "carbon production".
After five years of research and development, Great Wall has perfected the integrated supply chain of "research-manufacturing-storage-transportation-adding-application" , achieved complete independence of the intellectual property rights of the six core technologies and products of "electric stacks and components, fuel cell power generation and components, type IV hydrogen storage bottles, high-pressure hydrogen storage valves, hydrogen safety, and liquid hydrogen technology", and got rid of the technology The "stuck" stage. Among them, the hydrogen power platform (HE), stack platform (HS) and hydrogen storage platform (HP) are the main components of hydrogen fuel vehicles, and they can be regarded as the electromechanical power of fuel vehicles. The working principle is also similar to the way extended-range electric vehicles rely on the engine to generate energy to store energy or provide functions to the motor. The most difficult redeeming component in the entire process is the membrane electrode, which is the direct factor that determines the power of the hydrogen fuel cell generator, and the power density of the Lime platform reaches 1.2W/cm2 (the international mainstream level is 1.04W/cm2) ;The amount of platinum used is Pt＜0.3mg/cm2 (international mainstream Pt＜0.4mg/cm2), ensuring the dual effects of improving efficiency and reducing costs. Its comprehensive performance level has even surpassed the industry benchmark Toyota Mirai.
In addition to hydrogen energy, Great Wall has also begun to make efforts in hybrid technology. A few years ago, the Weipai P8 Ceng has been involved in the field of plug-in hybrids. When powered, the driving quality of the vehicle is excellent, but when powered down, it will reveal technical disadvantages. Now DHT hybrid has begun to be adapted on Macchiato, Latte and other models. In fact, whether it is Toyota THS, BYD DM-i or Great Wall DHT, they all have common technical ideas. They all hope to combine the most efficient range of the fuel engine and the output characteristics of the motor to achieve the best fuel efficiency ratio. From a technical perspective, the structure of Great Wall DHT is not complicated. It consists of a hybrid dedicated engine (only applicable to the highest fuel efficiency speed), a generator, dual driving motors, a two-speed gearbox, and dual motor control.controller and integrated DCDC. The drive mode supports EV, series, and parallel. The pure electric mode is the same as the electric car. The series mode uses a high-fuel-efficiency engine to generate electricity for the motor to propel the vehicle. The parallel mode is driven by the motor while the engine is driven by a two-speed transmission. The box drives the wheels. Logically speaking, the part that consumes the most fuel uses electricity, and the part that consumes the most electricity uses oil, thus maximizing the use of energy. Of course, due to the blessing of the motor and the exaggerated speed ratio, vehicles powered by DHT also have excellent ride comfort and a smooth power experience.
In addition to the development of hydrogen energy and hybrid power, pure electric technology is naturally Don't be left behind. Since BYD's blade battery became popular, various brands have also introduced their own battery technology, and the acupuncture test, which was not taken seriously before, has become standard. The Great Wall Dayu battery released during the year was named after its design concept. The optimization idea of battery cell control also comes from "Dayu's flood control", which changed blockage into dredging. In order not to reduce the energy density, Great Wall uses high-nickel ternary 811 batteries with poor stability, but adds double-layer composite materials to block heat in the battery core, and adds a fire extinguishing box design at the tail to prevent thermal runaway inside the battery. In order to ensure the rationality of the design, technical verification was also carried out by building a combustion model, fitting simulations of thermodynamics and fluid mechanics, simulations, and calculation of impact strength and pressure. If thermal runaway is triggered, the BMS and cloud system can also identify the thermal runaway of the battery core and quickly control the temperature through the cooling system to ensure absolute battery safety.
In terms of charging, at the Guangzhou Auto Show not long ago, the launch of the Mecha Dragon model of Great Wall's Salon brand also revealed the future. Introducing 800V fast charging technology with a peak current of up to 600A. After 10 minutes of charging, CLTC can achieve a range of 401 kilometers. Although the specific details have not yet been announced, it is not difficult to find from the data that Great Wall should have broken through the technical barriers of efficient charging components, but currently more constraints still come from infrastructure equipment with low charging power.
GAC Aian
Like BYD Great Wall, GAC Aian was also released this year And it is equipped with its own new generation power battery technology - magazine battery. The cell of the magazine battery can be compatible with lithium iron phosphate or ternary lithium. The structural layout of placing the cells one by one in the safety cabin is like a magazine, which is why it got its name. In order to ensure the safety between battery cells, aviation-grade silica-grade high-temperature-resistant nanomaterials are used. Therefore, it has the characteristics of high-temperature resistance and heat insulation, and can play a flame-retardant and heat-insulating effect. It can be easily used with the cooling system. Well control the operating temperature inside the battery pack. In fact, from a structural point of view, it has similar support to BYD, and the self-rescue process of thermal runaway is similar to that of Dayu battery.
Of course the magazineThe concept of the pool is more about solving safety issues, and as a technology to increase battery life, GAC Aian has also recently released solutions in sponge silicon anodes, and the GAC Aian LX plus using this technology has pushed NEDC battery life to 1008 kilometers, the battery capacity has also reached 144kwh. From a technical perspective, graphite has always been the main medium for battery energy storage. Silicon is more than 10 times more powerful than graphite, and the service life of lithium-ion batteries using silicon electrodes is about 30% longer than that of lithium-ion batteries using graphite electrodes. However, batteries using silicon materials have greater internal pressure during charging, and the silicon itself will expand three times, so safety has always been a problem. Sponge silicon can suppress this problem to a certain extent due to its porous structure. Although it will be slightly weaker than ordinary silicon batteries, it is still better than graphite batteries. Therefore, adding this design can increase the capacity of the lithium-ion battery anode. Nearly 50% extra capacity.
As for charging, GAC Aian has released the anticipated 3C 6C super-speed fast charging technology. This C is called the "charge rate", which is the multiple of the charging current relative to the rated capacity of the cell. The higher the charge rate, the faster the charging time. In short, how many C it can reach depends on the car’s battery capacity and the upper limit of the charging power it supports. If your car uses a 50kWh battery pack and the charging power can reach 150kW, it can be called 3C, and if the charging power can reach 300kWh, it can be called 6C. Of course, in addition to requiring vehicles to withstand higher charging power, super-fast charging also has hardware requirements for charging piles. At present, the more common State Grid charging piles generally remain at the 40-60kW level. So GAC launched the A480 charging pile. 480 is the peak charging power of 480kW. Its maximum current can reach 600A and its maximum voltage can reach 1000V. There is also a certain amount of redundancy in the design performance. Of course, the problem that comes with high-power charging is overheating. In order to ensure safety, Aion's A480 electric pile also uses lightweight liquid-cooled cables to ensure a safe working temperature. In addition, the charging level is not always carried out at the maximum power, but also needs to change the power in real time according to the capacity and temperature of the vehicle battery system itself. Basically, it can be maintained at more than 450 kilowatts before it is fully charged to 80%, with the most commonly used 30%-80%. The charging range basically only takes 4-5 minutes, and the charging efficiency is quite high.
Nio
Nio has been developing on two fronts this year , while vigorously promoting the construction of second-generation battery swap stations across the country, it will focus its research and development on batteries. However, unlike the previous three companies, since the core of Weilai's brand is to create a better car experience, the main changes in the battery are the structural matching and overall capacity of the battery pack. Before the release of the ternary lithium iron battery pack at the end of September this year, the 70 kWh and 100 kWh batteries promoted by NIO were both ternary lithium battery packs, while the new 75 kWh ternary iron lithium battery pack broke thethis combination. From the perspective of the battery itself, a hybrid battery pack is formed by cross-arranging mixed packages of ternary lithium and lithium iron phosphate. The external size of the entire battery pack is no different from the previous 70 kWh ternary lithium battery pack, but the overall capacity has increased by 5 kWh, the volume utilization of the new battery has increased by 5%, and the energy density has also increased by 14%, reaching 142Wh/kg. In addition to increasing the overall battery life by 30 kilometers, new structures such as temperature differences of different battery cells, new PTC heating elements in the battery pack, and internal integration of DCDC can also be used to reduce low-temperature battery life losses by 25%, and the SOC estimation is more accurate.
There will also be breakthroughs in solid-state batteries. NIO’s first pure electric car, which will be launched next year, will be equipped with a The 150kwh solid-state battery has an energy density of up to 360kWh/kg, which enables the battery life to exceed 1,000 kilometers. However, this solid-state is actually what Weilai calls it, because there is currently no specific mass production adaptation for real all-solid-state batteries. At the same time, aspects such as reliability and safety are also in the verification stage, and they do not have the ability to mass-produce. . NIO's 150kwh solid-state battery is just a transition from traditional lithium batteries to all-solid-state batteries. Strictly speaking, it is composed of a mixture of solid electrolyte and electrolyte. The structure also retains the separator and other parts of traditional lithium batteries, so it uses " The naming of "semi-solid" battery is actually more appropriate.
Xpeng
Xpeng at the battery level There is no substantial technological breakthrough, and it mainly relies on suppliers to provide lithium iron phosphate and ternary lithium battery packs. However, there is indeed a breakthrough in fast charging technology. At the recent Guangzhou Auto Show, Xiaopeng G9 also announced 800V silicon carbide fast charging technology. In fact, silicon carbide SiC has a wide range of applications. It not only improves the efficiency of the motor, but is also the key to increasing power in the charging process. On the Xiaopeng G9, the design of charging and discharging electrical components is developed according to the 800V level. The theoretical peak value can reach 800V, and the maximum current can support more than 600A during overcharging. For this reason, Xiaopeng has developed technology The resistance of high-voltage connections in each link has been reduced, and a blocking protection system has been added just in case. At the same time, like GAC Aian, it has also upgraded and improved the charging pile, adding a liquid cooling system to the charging cable charging gun. However, at present, Xpeng's supercharging technology is still in the technical verification stage and has not yet been officially launched on the road. The related supporting charging infrastructure is still in the early stages of development. Whether it is reliable or not will not be known until next year at the earliest.
CATL
When it comes to battery professionals, CATL is the most unavoidable this year The only technology is sodium-ion batteries. The reason why sodium-ion batteries are developed is on the one hand the need for future technology and higher energy density, and on the other hand it is also to no longer be controlled by others. The current battery pack requires a large amount of raw materials.Amount of rare metals such as Class I lithium, cobalt, manganese, etc., and my country is not the main producing area. Not only the price of raw materials fluctuates greatly, but also technical bottlenecks arise quickly. The sodium-ion tram is different. It not only breaks out of the bottleneck in technology and raw materials, but as a technical route for energy storage, it is safer and cheaper. Moreover, sodium-ion batteries have many advantages. Compared with the two major types of batteries at this stage, the energy density of a single cell of sodium-ion batteries can easily reach 160Wh/kg, and its stability is also very high. After charging for 15 minutes at room temperature, the battery capacity can reach 80%. In a low temperature environment of minus 20°C, there is still a discharge retention rate of more than 90%. In the future, the mass-produced sodium-ion battery will further increase the energy density to more than 200Wh/kg, and will be mass-produced in 2022. If everything goes well, it will be adapted to a variety of new vehicles in batches in 2023.
In addition to the upgrade and safety issues of the battery system that receive more attention, the reliability of the motor battery control system also It has become the key to the current technological upgrade. The motor and BMS technologies of major independent brands are constantly being upgraded. In the past, the motor, electronic control, and reducer in the electric drive system were limited by factors such as oil to electricity or space, and were more independent layouts. In recent years, various companies have been developing pure electric platforms, which are more suitable for highly integrated electrical systems in terms of structural layout. Following this, more and more three-in-one, four-in-one and even eight-in-one ultra-high-definition products have been developed. Integrated electric drive system.
Ideal ONE/GAC Aian LX
The 2021 Ideal ONE launched this year uses the latest three-in-one electric drive. This technology not only makes the rear axle space of the Ideal ONE more compact, but also changes the weight, freeing up more space for The fuel tank part is given, which directly improves the vehicle's endurance performance. Of course, there are many car companies that use similar three-in-one technology for high integration. The modular structure not only makes better space utilization, but also plays a role in motor speed, electric energy conversion efficiency, mechanical space compaction, and wiring harness simplification. Great effect.
For example, the "four-in-one" integrated electric drive of GAC Aian V also uses the same logic, by combining dual motors , controller and two-speed reducer are highly integrated to achieve an output power of 340kW, a comprehensive drive efficiency of 90%, a power increase of 13%, a volume reduction of 30%, and a weight reduction of 25%. The first model applying this technology also went on sale this year.
BYD Dolphin
Of course, BYD's "eight-in-one", which is at the forefront of high-level integration, has to be talked about. BYD Dolphin, launched this year, is equipped with an eight-in-one electric drive for the first time. Compared with the traditional motor electronically controlled reducer, it also integrates an on-board charger.Electric appliances, DC converters, distribution boxes, vehicle controllers, battery managers and other components are more deeply integrated based on the traditional three-in-one electric drive to achieve deep integration of software and hardware. This high degree of integration reduces the total volume of the electric drive system by 16% and the total weight by 10%, which means it can be adapted to a wider range of models and consumes less energy.
NIO ET7
As mentioned earlier, NIO’s solid-state battery has to be Let’s talk about another black technology of NIO ET7 that uses solid-state batteries, the silicon carbide superconducting electric drive system. This system is NIO's second-generation electric drive system, with "Silicon Carbide SiC" as the core. This wide bandgap semiconductor material has the advantages of fast switching speed, high turn-off voltage and strong high temperature resistance. Silicon carbide SiC is mainly used in the main drive of 180kW permanent magnet synchronous motor. It has three major characteristics: higher efficiency, higher performance and quieter. Since silicon carbide power devices can greatly improve the efficiency and power density of the permanent magnet synchronous motor drive system, it can also reduce the comprehensive loss of the electronic control system by 4% to 6%. The CLTC operating efficiency is greater than 91.5%, which has improved the ET7 city to a certain extent. Power consumption performance under working conditions. Of course, in addition to the application of silicon carbide components, the performance of ET7 has been greatly improved by optimizing the electromagnetic motor scheme, changing the speed ratio of the reducer, and accurately predicting the module life. At the same time, the internal optimization of the motor, gear optimization and noise optimization have also comprehensively improved the NVH performance of the second-generation motor unit. Compared with the previous generation electric drive, the noise has been reduced by 5-15dB.
In addition to technological upgrades in battery motor charging and other aspects, there are also many brands that are integrating future technologies. We are actively doing research and development. Of course, in addition to traditional car companies and new forces building cars, there are also some entrants to the industry. The technologies involved are mainly assisted driving, commercialization of autonomous driving, and smart cockpit technology.
Weima AVP autonomous parking
At this stage, it can realize automatic car following There are many assisted driving models, but not many can achieve fully autonomous parking. Among them, the AVP system of the WM W6 is very interesting. By learning the pick-up and drop-off points and parking in and out of designated parking spaces, you can achieve fully autonomous parking within 100 meters. The entire process does not require a driver. Avoiding road risks can also be handled by the vehicle itself, which can be said to be a solution. It solves the parking problem for many people. This AVP system is realized through the joint efforts of 2 high-definition cameras, 4 surround-view images, 5 millimeter-wave radars and 12 ultrasonic radars, and the data coordination operation is performed by the computing power of Qualcomm's 8155 chip and platform. The computing power of this chip can reach 3.6 million times per second, and its performance is powerful. In fact, the Mercedes-Benz S-Class PAVP parking system and the BMW 3 Series' 150-meter original path reversing have similar technical routes. However, Weimar’s AVP system is obviously improving in terms of maturity and security.Better overall.
Xpeng XPILOT4.0
We mentioned Xpeng’s G9, in fact, when the G9 was released, more technical details of Xpeng XPILOT 4.0 were also mentioned. To put it simply, Xpeng XPILOT2.5 is a system with a variety of driving assistance functions. XPILOT 3.0 and 3.5 are the development process from high-speed NGP scenarios to urban NGP scenarios. Simply put, they can rely on vision, high-precision maps and multiple This kind of radar completes automatic lane changing and navigation assistance at intersections. The full-scenario intelligent assisted driving of XPILOT 4.0 further integrates the entire scene, making the intelligent driving process seamless. The hardware is replaced with new lidar and two Orin-X autonomous driving chips, and the computing power is increased to 508 TOPS. The binocular camera has been upgraded to 8 million pixels, and a 2.9 million pixel perception camera has been added to the body. Through the continuous optimization of hardware redundancy and algorithms and high-precision maps, higher-level assisted driving capabilities are achieved. If the software and hardware of XPILOT4.0 can be opened as soon as possible, it will have more powerful assisted driving functions than Tesla FSD.
Baidu Apollo driverless
Different from the assistance of major car manufacturers In terms of driving, Baidu's Apollo driverless technology has been put into road testing earlier, and has completed tens of millions of kilometers of road testing in specific areas in many places. The test vehicles and technology have also been updated for the fifth generation. At present, Baidu has carried out in-depth cooperation with companies such as Jihu and Weimar, and has launched various customized versions of Apollo Moon mass-produced shared unmanned vehicles. The most important thing is that they are unmanned vehicles that can be put into large-scale operations. Taking Jihu αT as the carrier of Baidu Apollo's fifth-generation driverless vehicle as an example, the vehicle cost 480,000 yuan. In addition to the original body parts, it also added multiple sets of lidar, visual cameras and a more powerful computing platform. Excess hardware redundancy to ensure product safety and reliability. At the same time, multiple sets of sensors outside the car are also equipped with self-checking and self-cleaning functions, which can ensure the normal operation of the system in special environmental climates. If a core component fails, the detection system will promptly implement a downgrading strategy for the corresponding component. At the same time, it also supports 5G cloud driving, V2X and other functions. Baidu officials stated that this model can operate stably for at least 5 years (about 20,000 hours), and the average hardware cost is only about 8,000 yuan per month.
Huawei Hongmeng Smart Cockpit
As a crossover player, Huawei has come up with HarmonyOS smart cockpit system. Facing the AI era, combined with the unique characteristics of smart cars, a smart cockpit vehicle domain system has been created. This system takes driving safety as the basic principle and combines intelligent services and HMS-A's rich capabilities with HarmoThe nyOS vehicle domain application ecosystem is brought into the cockpit, bringing a more convenient development environment and greater value opportunities to a wide range of developers, bringing users a diversified smart cockpit experience, and creating a "people-car-home" full scenario Seamless connected experience. At the technical level, the smart cockpit covers smart car and machine, car and machine hardware, car and machine system, car and machine application software ecosystem, car and machine mall, AR-HUD, audio and other aspects, and almost completely integrates our riding, use and even consumption in the cockpit. All considered. Of course, Huawei's ambitions don't stop there. The first model equipped with Huawei's HarmonyOS smart cockpit system is currently in the final verification stage and will be available in early 2021. Moreover, it is a new medium-sized model led by Huawei and put into production by Jinconcelis. SUV. At the same time, Huawei's HarmonyOS smart cockpit system will also provide in-depth customization according to different brands and models to ensure the independence of the UI and the product characteristics of different brands.
It must be said that the technological changes of new energy vehicles will advance by leaps and bounds in 2021, from energy storage to energy supply to assisted driving to all aspects of the vehicle. , all are undergoing comprehensive innovation. Of course, during this process we can also see that many traditional car companies have not realized the seriousness of the problem and are still stuck in their thinking. Maybe the traditional way of building cars will still be useful in the next five years, but we might as well look forward and see how much has changed in the past five years. If we don't make a change in thinking, maybe next year when we do a technical inventory, it may look different.