The problem of battery decay has been the focus of the current new energy market, and Japan is the first to start from the car companies to "prescribe the right medicine."
Recently, the Ministry of Economy, Trade and Industry of Japan plans to require auto manufacturers to display the battery life built into pure electric vehicles, so that drivers can understand the attenuation of re-used and aging lithium batteries through the driver's seat display, and strive to establish a suitable battery capacity evaluation. The mechanism promotes the reuse of batteries while cultivating the second-hand market of pure electric vehicles.
The guidance plan will be announced as early as September and will be formally decided during the year. All automakers will also respond positively, and the remaining capacity of the new car will be shown in the new car developed in the future.
Take the Nissan pure electric vehicle "Leaf" currently on the market as an example, the capacity of the fully charged battery will be displayed on the 12-level scale to compare with the new car battery. On the other hand, there are also pure electric vehicles that do not display battery capacity like the wind.
The Ministry of Economy, Trade and Industry of Japan plans to require each car company to display the reduction in battery capacity like the wind, or to a lesser extent than the single-charge cruising range at the time of purchase.
The problem of battery attenuation has been the focus of the current new energy market, and its attenuation affects the normal use of vehicles. This problem is even worse at low temperatures.
The actual measurement shows that under the conditions of simulating low-speed road conditions in the city, maintaining the outside temperature of -7 °C and the temperature of the car at 20~22 °C, the measured life is less than half of the nominal. The simulation conditions of this test are more stringent, but it is more suitable for the driving situation of winter driving. It can be seen that in the low temperature environment in winter, the actual life of new energy vehicles (especially pure electric vehicles) will be greatly reduced.
Affected by battery attenuation, the new energy vehicle's hedge ratio is very low. A report released by the agency recently showed that the new energy vehicle's three-year insurance rate is only 20%. Compared with fuel vehicles, the low maintenance rate of electric vehicles is the consensus in the industry.
In order to cope with this problem, most car companies are committed to optimizing the battery management system (BMS), in a low temperature environment, a part of the power is converted into heat, the entire battery pack is heated, which to some extent improves the battery attenuation at low temperatures. The problem.
In the winter car, if the consumer turns on the warm air conditioner before driving and charging, this can also increase the temperature of the battery itself, thereby obtaining higher cruising range and charging efficiency.
In addition, if the battery is cured, the attenuation can be slowed down, and the battery attenuation is only 20% within five years. For example: use less fast charge, fast charge voltage, it is easy to cause the battery to overcharge to deposit lithium ions on the surface of the diaphragm or electrode, and the high temperature during fast charge can easily cause irreversible effects on the battery; or keep the battery at normal temperature (0 Work at -40 ° C) to reduce side effects.
At present, in addition to causing Japan's attention, the problem of battery attenuation is also in the process of formulating quality assurance standards for battery attenuation.
In March of this year, the State Administration of Market Supervision issued a revised draft of the “Three Guarantees” to include the powertrain and main components of household electric vehicles in the “three guarantees” responsibility of automobiles. The revision of the "Three Guarantees" also stipulates that the state intends to stipulate the battery attenuation of electric vehicles, and requires the production enterprises to express the battery attenuation limit and the corresponding test methods on the "three guarantees" certificate.
Among them, the quality assurance standard related to power battery attenuation is expected to be released and implemented this year.