Economic Observation Network reporter Pu Zhenyu On December 31, 2021, China Automotive Engineering Research Institute Co., Ltd. (hereinafter referred to as "China AutoMotive Research Institute") and the National Big Data Alliance for New Energy Vehicles released a white paper saying that the low-temperature attenuation data of 53 new energy vehicles at home and abroad in the past 10 years showed that during the period from 2012 to 2021, the average value and distribution range of the low-temperature mileage retention rate of new energy vehicles did not change significantly, 65.38% The mileage retention rate of new energy vehicles in low temperature environment is about 52.8%-67.2%.
Wang Peng, head of the evaluation procedures of China Automobile Research Institute new energy, said at the white paper press conference that under the premise of continuous improvement of battery energy density and vehicle mileage, the problem of mileage anxiety in the traditional sense has been basically solved, but how to alleviate and improve the shrinkage and even jump in winter mileage and improve the driving experience of consumers in winter is another pain point that consumers care about in addition to safety of new energy vehicles.
At present, the mainstream power battery types used in new energy vehicles include lithium iron phosphate batteries and ternary lithium batteries. It is understood that in the low temperature environment, the diffusion ability of lithium ions in the electrolyte will be reduced, which will cause an increase in current loss, resulting in a loss in the mileage of new energy vehicles, and in the case of extremely cold temperatures, the power battery of new energy vehicles may even stop working.
For the lithium battery "afraid of cold" caused by the shrinkage of battery life, Ouyang Minggao academician workstation chairman Hua Jianfeng said that to solve this problem in essence, it is necessary to change the material and use some new electrochemical methods, but it is not realistic to achieve such a goal at present, and at this stage can only solve the problem from the means of management and physics, including strengthening the construction of charging piles and promoting the integration and development of the vehicle network.
In 2021, the sales volume of domestic new energy vehicles will increase explosively, and the contradiction of "vehicle-to-pile ratio" will be further prominent. According to the data, at the end of 2020, the "vehicle-to-pile ratio" of domestic new energy vehicles was 2.9:1 (with 4.92 million units and the number of charging piles was 1.681 million units), while at the end of June 2021, the vehicle-to-pile ratio of domestic new energy vehicles expanded to 3.1:1. According to the requirements of the charging pile construction task arranged by the National Energy Administration's Development and Reform Commission, the "vehicle-to-pile ratio" will reach 2:1 by 2030.
Wang Zidong, an expert of the New Energy Vehicle Production Access Review Group of the Ministry of Industry and Information Technology, suggested that the problem of new energy vehicles in winter should be alleviated through the power exchange mode, he said, "Now the Ministry of Industry and Information Technology is promoting power exchange standards, and the construction standards for shared power stations have been released, which is also to solve the problem of how to deal with low temperatures (with cars)." The most important thing in winter is that it can't be charged, the power exchange mode is particularly suitable for B-end users, they have charging needs every day, the original charge once a day becomes charged twice a day, it will be very uncomfortable."
Recently, the China Association of Automobile Manufacturers and the China Electric Vehicle Charging Infrastructure Promotion Alliance organized the relevant units to compile and recently officially issued the "Electric Passenger Car Sharing and Replacement Power Station Construction Specification" group standard, providing a "standard template" for the construction of the replacement power station.
In addition to the technical characteristics of the lithium-ion battery itself that is "afraid of cold", the heating function is also a major "killer" of the winter new energy vehicle endurance. Different from the waste heat heating method of traditional fuel vehicles that rely on engine cooling water circulation, the heating method of new energy vehicles is relatively single. A study by a US authoritative institution cited in the white paper shows that the use of electric vehicles in low temperature environments and the opening of warm air will reduce the vehicle's driving range by more than 40%.
For this problem, Liu Xiaoshi, deputy secretary-general of the China Electric Vehicle Hundred Association, said at the press conference that the heat pump air conditioner used in the construction industry can increase the energy-saving effect in winter by about 30%, but due to the price problem, it is more difficult to promote electric vehicles, and it is recommended to increase air conditioning energy consumption and winter mileage projects in the test of electric vehicle products, and mark them in product parameters to better promote the application of such high-efficiency air conditioners.
According to the data, the "heat pump air conditioner" is an air conditioner with a heat pump, and its heating and cooling efficiency are higher, but the manufacturing cost is also higher than that of ordinary air conditioners. However, in the past two years, BYD, Weilai, SAIC-GM-Wuling, Volvo, Volkswagen and other car companies have begun to use heat pump air conditioning in their electric vehicle products.
How much energy consumption can the use of heat pump air conditioners help new energy vehicles save? Shao Jie, chief technology officer of the intelligent platform of SAIC-GM-Wuling Technology Center, said at the press conference that SAIC-GM-Wuling plans to upgrade its new energy models to the vehicle's all-climate intelligent heat management system, and develop more efficient heat pump air conditioning and waste heat recovery technology, which can reduce the energy loss caused by heating of more than 55% of the vehicle.