Electric cars fall into the "high-end trap"?

Recently, the frequent occurrence of electric vehicle battery fires everywhere has cast a shadow on the booming electric car. On November 9th, Yang Yusheng, an academician of the Chinese Academy of Engineering, pointed out that the underlying reason behind the frequent battery fires may be the development direction of China’s electric vehicles at the media forum of the Challenge and Opportunities for China's Lead-acid Battery Industry sponsored by the NGO Global Village. Problem. Electric cars seem to have fallen into a "high-end trap."

Electric car ignited sparked consumer doubts

On September 3 of this year, a hybrid double-decker bus that was put into operation in Shenzhen for less than 20 days suddenly emitted smoke when it reached the city's Zhuzilin section. In order to prevent the possible consequences of design defects causing more consequences, this type of vehicle was stopped. According to the “Southern Metropolis Daily” report, Wuzhou Dragon, a manufacturer, said that this is only a small issue of insurance blown.

This is not the only new energy vehicle that recently experienced spontaneous combustion and smoke accidents. On July 18, a pure electric bus of the 825 road near Zhongshan Park in Shanghai spontaneously ignited. According to the report of the “First Financial Daily”, the fire point was roughly at the location of the capacitor box at the lower left of the vehicle. Yan Yuan, deputy general manager of Shanghai Leibo New Energy Automotive Technology Co., Ltd., said that it is a problem with lithium iron phosphate batteries on vehicles. According to Luo Qinghua, a battery manufacturer in Shenzhen Shanmu Technology Co., Ltd., “The combustion is not a battery problem, but the batteries inside the battery are too much and the ventilation is not enough, causing the battery temperature to rise, causing the battery casing to ignite spontaneously at high temperatures.”

New energy vehicles with similar problems are not just buses. On April 11 this year, a running Zhongtai Long Yue pure electric taxi caught fire in the streets of Hangzhou. The following conclusions of the appraisal show that: “The occurrence of auto-ignition accidents cannot be considered as having quality problems in the design and manufacture of battery cells. However, after the batteries are grouped, they cannot fully meet the needs of the vehicle use environment. During the application process, battery leakage and insulation have occurred. Damage and partial short-circuiting, and failure to find it in time, after repeated use, hidden dangers appear, causing the accident."

Sudden incidents of spontaneous combustion of new energy electric vehicles have caused consumers' doubts. After the accident of smoking and stopping of the Shenzhen hybrid bus, there was insufficient time for users to question the commissioning of vehicles. It is believed that this type of car still needs a lot of practice and adjustment. Before that, "Don't let passengers act as experimental items."

In this forum, Yang Yusheng, a renowned battery power expert and an academician of the Chinese Academy of Engineering, said that behind the repeated fires of electric vehicle battery packs, there are deep-seated mechanisms and conceptual reasons. This is a reversal in the current development of electric vehicles. The order of confusion.

Electric vehicle development direction leads to controversy

Academician Yang Yusheng believes that the current research and development of electric vehicles, battery and vehicle R & D investment positions are reversed, eager for quick success, and battery R & D itself there are power batteries and fuel cells in the reversed position, wrong mistakes. “Relevant departments are enthusiastic about industrialization and demonstration operations, but they ignore the fact that cutting-edge technologies are not yet mature and the engineering foundation is not firmly established.” Academician Yang Yusheng said that in his opinion, batteries are the main factors determining the performance of electric vehicles. Factors, and currently China's battery technology is still facing a lot of bottlenecks, the current development of lithium iron phosphate battery with high specific energy, but the technology is still relatively immature, and its high security advantages are also relative, the battery is an energy-contained components It has dangerous nature.

Although faced with battery limitations, Chinese automakers are still embarking on the road to electric vehicles, starting with veteran car makers FAW, SAIC, battery-started BYD, and start-up parts manufacturing, the first batch of selected countries. “Zhongtai” of the “Guided Catalogue of Recommended Models for Energy-Saving and New Energy Vehicles for Demonstration, Promotion, and Application of Projects”...... The electric vehicles produced by these companies, whether they are family passenger vehicles or large buses, have been promoted to have the same performance as the fuel vehicles, and more. Good economy. For example, the famous BYD E6 has a range of 300 kilometers, consumes 19.5 degrees per hundred kilometers, and costs nearly 400,000 yuan.

However, in Yang Yusheng’s opinion, electric vehicles are required to have the same maximum speed, cruising range, and acceleration time as the fuel vehicles, but they must also have fast charging performance. This is actually unrealistic. To raise the standard to a high level, on the surface it is to maintain electric vehicles. In fact, it is harming it. Professor Guo Konghui, who is also an academician of the Chinese Academy of Engineering, has drawn a map of the weight, speed, mileage, and battery of electric vehicles. According to Zhang’s calculation, according to the specific energy that can be achieved by the current battery, the most suitable speed of the electric vehicle is 100 km/h and the cruising range is 150 km.

"Because of the current limitations of battery technology, even if it is an advanced lithium battery, its specific energy is still limited. If we want to run fast and go far, we must increase the number of batteries, increase the number of batteries, and increase the weight of the vehicle. Increasing the number of batteries will create a vicious cycle. With the increase in the number of batteries, heat dissipation will be more difficult and the danger will increase.” Yang Yusheng said that letting electric vehicles go to sell medium-to-high-grade fuel vehicles that also sell three or four million yuan. Competition, market competitiveness will certainly not work.

Miniature Electric Vehicles is a feasible solution at this stage

According to Yang Yusheng's view, the current problem of low cost-effectiveness and hidden safety problems in mainstream electric vehicles is, in the final analysis, four words: (cars) are too large and (required) too high.

The solution is to develop miniature and small electric vehicles. "Its goal is to upgrade bicycles, electric bicycles, and motorcycles. It can shelter wind and rain, and it is mainly used for travel needs in cities. It does not require it to run for hundreds of kilometers." Yang Yusheng said that such vehicles are Its own light weight, low battery requirements, you can use cheap but mature lead-acid batteries with low specific energy, you can also use high-energy lithium batteries with higher prices. The use of lead-acid batteries as the power, the maximum speed of about 50 km / h, cruising range of 100 km, mini-car 100 km power consumption of 5-6 degrees, 100 km small cars consume 8-10 degrees, the price does not exceed 50,000 yuan; Lithium-ion batteries are powered by batteries that contain no more than 800 kilograms of battery and 120 kilograms of battery. They can run 200 kilometers at a time when they are fully charged. Prices are less than 80,000 yuan. No quick charge capability is needed, and you can use low-priced "Valley" at night.

Chen Qingquan, chairman of the World Electric Vehicle Association and academician of the Chinese Academy of Engineering, also stated that in the field of electric vehicles, there is still a gap between China and overseas car giants. China's electric vehicle companies can adopt another route, that is, develop markets with low technical requirements, low barriers to entry, and no technical barriers at the same time, and make the company bigger and stronger as soon as possible. From the current situation in China, low-income people have high demand for cheap electric vehicles. If the development of low-speed small electric vehicles meets people's needs for transportation, there will be good opportunities for industrial development.

In fact, such small-scale low-speed electric vehicles have been welcomed by consumers in small and medium-sized cities and rural markets in Shandong, Zhejiang, Jiangsu, and Guangdong, and have a large number of producers and have already been exported in bulk.

Yang Yusheng said, “The high-end electric vehicles are less competitive than the fuel vehicles. If we can develop small and micro electric vehicles first, and then form the market at the low end, and then seek further industrial upgrading, we will be able to develop sufficient competitiveness. "So I have always called on local governments to hurry up to establish industry standards for such miniature and small electric vehicles and give them licenses," Academician Yang Yusheng said: "This can form an electric vehicle industry with Chinese characteristics, and save a lot of money. Gasoline, reducing urban air pollution."

However, this is not easy. On the one hand, lead-acid batteries used in low-speed electric vehicles have recently caused a “supply storm” due to pollution problems of some manufacturers. As of July 31, 2011, it accounted for more than half of lead-acid battery production capacity. The company was shut down. What followed was a shortage of lead batteries and the price rose rapidly.

One issue that is worthy of attention is that the main and passive safety settings of micro- and small-sized electric vehicles are difficult to classify as compared to traditional power models, and this is one of the reasons why they cannot properly license. In addition, the "image" of such models is not accepted by most local governments, so the road to "license" has become increasingly bumpy.

● Glossary

What is the specific energy of the battery

Specific energy refers to the amount of energy that can be output per unit mass or unit volume of the battery. The unit is Wh/kg or Wh/L, respectively. Specific energy has the ratio of theoretical specific energy to actual specific energy. The former refers to the energy that can be output when 1kg of reactive material is completely discharged; the actual specific energy is the actual energy that can be output by a 1kg battery. Due to various factors, the actual specific energy of the battery is far less than the theoretical specific energy.