Author: Hu Yan Pan Liang Source: jinyang.com

Recently, Mr. Zhong, a budding car owner in Guangzhou, told the Yangcheng Evening News that he was worried that fast charging overcharging would seriously depreciate battery life and would only choose slow charging in the future. The reporter visited the market and found that there are many car owners who have such concerns. In addition, there are also rumors on the market that "new car charging to first exhaust the electricity" and so on.

Clarify the facts, crack the rumors, to enhance the quality of consumption, optimize the consumer environment, and help promote the development of production of related enterprises is beneficial. In addition, for the sustainable development of new energy vehicle batteries, charging piles and other aspects, this year's National People's Congress, the National People's Congress of the automotive industry, CPPCC members to offer advice on how to start from the "electricity" to help the high-quality development of new energy vehicle industry.

New car first charge to put out?

"New car charging to first exhaust electricity, from zero to a hundred", in the new energy vehicle consumer market, rumors like this still exist. The creation of this rumor can probably be traced back to the non-smartphone era.

At that time, cell phones used nichrome or NiMH rechargeable batteries, and consumers were used to running out of charge before recharging them fully on the first charge. It was widely said that these batteries had a certain "memory effect" and that if the phone was charged when the electricity was not used up, the battery contents would crystallize, making the battery "think" that it was dead, and in the long run, the battery capacity would decrease until In the long run, the battery capacity will be reduced until it can not store electricity at all.

Battery development so far, the batteries used in new energy vehicles are chemical batteries, common lead-acid, lithium titanate, lithium cobaltate, lithium iron phosphate, nickel cobalt manganese, nickel cobalt aluminum, which are five kinds of power batteries. And regardless of common electronic devices or new energy vehicles, lithium-ion batteries are the mainstream choice at this stage. Lithium compounds are used as electrode materials, and graphite is used as anode materials.

According to the Chinese Academy of Sciences Institute of Physics WeChat public number, in all commercial batteries, lithium-ion battery energy density (unit volume of stored electricity) and specific energy (unit mass of stored electricity) is the highest, at the same time, lithium-ion battery cycle life is very long, the excellent ternary material battery cycle life can reach more than 3000 times, lithium iron phosphate batteries can reach tens of thousands of times, a day a charge, then Can be used for 8 years and 27 years, respectively. In addition, lithium-ion batteries have the advantages of light weight, low pollution and no "memory effect". In other words, the new energy vehicles using such batteries do not need to use up the electricity before filling.

At present, new energy vehicles can travel 100 to 200 kilometers in one full charge, and can be used for a day to a week before recharging. According to some 4S store clerks, the first charge can be full, and it is good to start charging when there is about 20% of power left. Most importantly, shallow charge shallow put more insurance, pay attention to avoid overcharge, overcharge, undercharge, according to the charger indicator color to determine whether you can charge. Therefore, it is also generally recommended that consumers choose to charge during the day in order to control the charging time.

Fast-charging super-charged battery will definitely break life?

As new energy vehicle production and sales and ownership continue to rise, the car-pile ratio remains high, resulting in "difficult to wait for piles" and "difficult to find a pile" during the holidays. Under the impetus of "charging anxiety", the era of super-charging of new energy vehicles has arrived, and China is accelerating the construction of charging facilities, with the number of charging piles in China increasing by nearly 100% year-on-year in 2022. With this comes another anxiety: fast charging overcharge will lead to battery folding life.

The so-called slow charging refers to AC charging, which generally takes 6 to 8 hours to fill the battery. Fast charging, super-charging refers to high-power DC charging, only half an hour or even less time, you can charge to 80% or more. A charge multiplier of more than 1C is generally considered fast charging. 1C refers to the full capacity of a battery, and 1C charging means that the battery is fully charged in 1 hour.

What is really closely related to battery health is mainly thermal management, BMS (Battery Management System), etc.

The book "Automotive Big Data Application Research Report (2021)" mentions that nine common factors that affect battery health include: current battery capacity, battery internal resistance, charge and discharge depth, charge and discharge rate, self-discharge rate, overcharge and overdischarge, cycle times, charge and discharge current and temperature. Among them, in terms of charge and discharge rate, when charging at high rates, the battery temperature may rise too fast, adding difficulty to thermal management and leading to deterioration of battery health.

The BMS is called the "protector" of the battery, which can detect and analyze the battery status to avoid over-discharge and extend the battery life.

The use of safe and reliable thermal management system, BMS, etc., can effectively protect the health of the battery. For example, the 2021 annual report shows that Ningde Times has owned and is applying for a total of 10,222 domestic and foreign patents, including modules, BMS, thermal management, thermal safety and other battery systems, etc. In November 2022, Ningde Times applied for the patent of "vehicle thermal management system and vehicle", which can regulate the temperature of the battery to improve the range. The technology can regulate the temperature of the battery to improve the range. Use the products and services provided by such large manufacturers, and develop good charging habits, then the normal fast charging super-charge for the battery loss can be relatively negligible.

Boost the battery industry to open the charging "blockage"

China is the world's largest new energy vehicle market. Power battery is considered the core of new energy vehicles, is the key link of the industry chain, and the rapid growth of charging infrastructure, effectively supporting the rapid development of new energy vehicles. Next, how to continuously promote the healthy development of power battery industry and optimize the layout of charging network is an important proposition to be solved.

In recent years, the domestic battery energy storage industry has grown rapidly, but the products are uneven.

National Committee of the Chinese People's Political Consultative Conference (CPPCC), Ningde Times Chairman Zeng Yuqun proposed to accelerate the power battery "passport" and supporting policy research, and pointed out that the battery storage needs nuclear power level safety protection. According to his vision, the "battery passport" is the digital twin of the physical battery, which can realize the transparent digital management of the whole supply chain of power batteries. Consumers and regulators can access the relevant information of battery products simply and directly through the "battery passport", which can provide a data base for battery carbon footprint, recycling traceability and gradual utilization.

National People's Congress, Changan Automobile Party Committee Secretary, Chairman Zhu Huarong suggested to promote the standardization of new energy vehicle power battery, accelerate the development of lithium resources and other mineral resources layout.

Meanwhile, at present, China has built the world's largest number and most widely distributed charging infrastructure network. Data from the China Charging Alliance shows that the average monthly number of new public charging piles in 2022 is about 54,000. By the end of September 2022, Guangdong Province had 345,126 public charging piles and 19,116 charging stations.

The demand for DC charging piles is also very strong. In the public category, at present, AC charging piles still dominate, but DC fast charging is expected to speed up development. According to the "2021 China Electric Vehicle Users' Charging Behavior White Paper" released by China Charging Alliance, DC charging piles have become the first choice of 99.3% of users.

Pan He Lin, a researcher and co-director of the Digital Economy and Financial Innovation Research Center at Zhejiang University's International Joint Business School, is optimistic about the future development of supercharging. Comparing power exchange and charging, he told Yangcheng Evening News that power exchange is more suitable for public rental transportation, but in the field of private cars, power exchange is not so suitable and the application scenario is not wide enough. Therefore, super-charging is the main direction of development for a long time to come.

However, public charging stations around the "hot and cold" "charging anxiety" is still widely present.

Liu Yong, director, general manager and deputy secretary of the party committee of State Grid Jiangxi Electric Power Co., Ltd, suggested that the construction planning of new energy vehicle infrastructure should be accelerated and improved, and the construction of charging facilities should be integrated into the urban and rural construction planning and scientific layout.

Zhang Zutao, director of the Engineering Training Center of Southwest Jiaotong University and executive director of the School of Innovation and Entrepreneurship, suggested organizing "zombie piles", releasing field stations and power capacity, and unifying charging APP.

Reprinted from http://www.batterychn.com/newinfo-1003-2