CATL, BYD compete in fast charging, power batteries will enter the 6C era

The charging speed of electric vehicle batteries is reaching a new height - 6C charging rate.

According to 36Kr, CATL plans to launch a second-generation Kirin battery product with a charging rate of 6C in the second half of the year. Companies like Li Auto, ZEEKR, and others have already had technical exchanges with CATL on the Kirin second-generation products, but have not yet decided whether to launch products with the corresponding technology this year.

At the same time, BYD, which has not released a new battery product for three years, is also preparing to launch fast-charging battery products. A source close to BYD told 36Kr that the second-generation blade battery from BYD may be launched in the second half of the year, "At the same time, BYD's 6C battery is also under development."

As for how to achieve 6C while also considering higher energy density, industry analysts say, "It is not ruled out to use a mixed material system of lithium iron phosphate + ternary, which is a new direction in the industry."

In addition to these two leading companies, Zhong Chuangxin had previously stated that by the end of 2023, the company will mass-produce the 46 series large cylindrical battery that supports a 6C charging rate in the fourth quarter of 2024, while the 5C battery that can replenish 80% of energy in 10 minutes will also be mass-produced and installed in vehicles in 2024.

In the battery industry, "C" refers to the charging rate. In theory, power batteries that support "several C" charging rates can fully charge the battery in a fraction of an hour. However, in actual charging processes, the peak rate is generally used as a standard, meaning that the peak rate during charging can reach "several C," which can be called "several C fast charging."

The Li Auto MEGA and the all-new ZEEKR 001 are equipped with CATL's 5C Kirin battery and 5C Shenxing battery, both of which can achieve a peak charging rate of 5C, basically being able to charge the battery from 10% to 80% in 12 minutes.

Nowadays, the battery industry has encountered technological bottlenecks, with traditional liquid batteries approaching the theoretical energy density ceiling, and solid-state batteries that support higher energy density materials applications are still unable to be mass-produced. Pure electric vehicles need more practical technologies to drive sales in the end market, and fast charging has become almost the only choice.

All car manufacturers and battery companies are striving to make charging as fast as refueling. From the 3C charging in 2022 to the introduction of 4C and 5C in 2023, electric vehicles are now advancing into the era of 6C.

How to Achieve 6C

Advancing towards 6C fast charging requires strong technological capabilities. It is necessary to not only improve at the level of cell materials but also upgrade at the battery system level.

Firstly, on the material side, fast-charging batteries need to be equipped with fast-charging graphite, electrolytes suitable for fast charging, separators, and other materials, and can also "mix and match" basic lithium iron phosphate and ternary materials to balance performance.

Some industry insiders analyzed to 36Kr that, for example, CATL's fast-charging batteries are mostly doped with less than 5% of lithium iron phosphate on the basis of ternary materials, as are the Kirin batteries of Li Auto MEGA and Xiaomi SU7, which can improve some safety and low-temperature rate performance The mixed use of ternary materials and lithium iron phosphate materials can to some extent combine some of the advantages of both, allowing for faster charging while also enhancing overall battery performance.

Furthermore, the higher the charging rate, the more heat the battery generates. Therefore, fast-charging batteries require a more powerful cooling system to suppress temperature and ensure safety.

CATL's Kirin battery architecture is centered around large-area liquid cooling technology. Different from the liquid cooling system laid flat at the bottom of the battery cells, the Kirin architecture places the liquid cooling plate between the battery cells, ensuring a larger area for heat dissipation and thus enhancing the performance of the battery pack.

At the same time, the liquid cooling plate in the Kirin structure is designed elastically to alleviate the expansion and contraction issues of the battery during charging and discharging. The Kirin structure increases the heat dissipation area of the battery pack by 5 times, with a maximum heat dissipation power of 16kW, ensuring effective battery cooling under high-rate charging scenarios.

BYD's research and development in battery system heat dissipation capability is also evident. One of BYD's most commendable battery cooling technologies is the use of direct cooling and heating refrigerants.

Recently, when BYD released the fifth-generation DM system, the accompanying new generation of plug-in hybrid blade batteries showed significant improvements in the direct cooling system.

In the previous generation of plug-in hybrid blade batteries, BYD used a T-shaped cold plate design that did not fully cover the battery pack, while the new generation adopts an S-shaped cold plate design with a larger heat dissipation area and better temperature uniformity.

Currently, BYD's models do not support fast charging rates above 4C, but the technological reserves are sufficient. BYD's style is to announce and then mass-produce without relying on future technologies. When it announces the mass production of 4C or even 6C batteries, its refrigerant technology may become a key factor.

Leading power battery companies such as CATL and BYD are all gearing up for 6C fast charging. However, the current dilemma may be the lack of supporting ultra-fast charging infrastructure.

Having Supercharged Cars, Lacking Supercharging Stations

Since the introduction of the XPeng G9 on the 800V platform in 2022, China's electric vehicle industry has seen a surge in charging speed. New models such as the XPeng X9, Li Auto MEGA, ZEEKR 001, 007, Xiaomi SU7, etc., all offer fast charging as a necessary option for consumers.

In terms of marketing, these cars are now promoting support for 4C or even 5C fast charging, but actual experience requires the cooperation of charging stations.

Currently, there are three types of charging stations on the market: slow charging, fast charging, and supercharging. The electric vehicle industry does not have a unified definition for "supercharging." Generally, the industry refers to charging stations with a power of 120kW or higher as "supercharging stations."

However, if we elevate supercharging to 4C or even 5C charging rates, the charging power needs to exceed 360kW. The maximum charging power of a 4C supercharging station is 480kW, with a maximum charging current of 615A. At this point, the number of charging stations becomes rare and precious, especially those that can support a 5C charging rate, which are even rarer.

Li Auto MEGA is one of the few models on the market that supports 5C charging. This model is very representative, as Li Auto CEO Li Xiang once stated on Weibo that the peak charging power of the Li Auto 5C supercharging station is 520kW, with an average charging power of over 400kW To enjoy such a fast charging experience, users need to support charging piles with a 5C rate. Taking the new energy vehicle hub Shenzhen as an example, according to the Li Auto app, there are only three Li Auto supercharging stations supporting 480kW, which is equivalent to a 5C rate, in the entire city. In total, there are only 3 5C charging piles.

Even if all third-party charging stations supported by Li Auto are included, Shenzhen only has 15 supercharging stations with 480kW charging power support.

This also means that even if users purchase models that support 4C or 5C charging rates, due to the scarcity of supercharging piles at the moment, it is difficult to have a corresponding experience.

Car manufacturers and industry chain companies are working hard to solve these problems. For example, Huawei is pushing for the deployment of over 100,000 fully liquid-cooled ultra-fast charging piles by 2024, with a maximum output power of 600kW and a maximum current of 600A. Companies like Nio and ZEEKR are also actively promoting the construction of supercharging piles.

However, building supercharging piles that support 4C, 5C, or even 6C rates will involve issues with grid capacity. If energy storage is used, it will lead to increased costs, and it seems difficult to solve this issue with just a few companies. Therefore, charging piles remain one of the key factors restricting the application of supercharging.

Simply increasing the charging rate at the vehicle end to improve charging speed while lacking proper support at the pile end makes the statement "charging as fast as refueling" just empty words.

At a time when there are not many charging piles to choose from for models that support a 5C rate, the appeal of 6C in practical applications seems limited.

However, the technological trend has emerged. After the mass production of CATL's Godsend battery in multiple pure electric vehicle models, BYD's breakthrough in the high-end pure electric market clearly puts more pressure, so the three-year-old blade battery is also targeting fast charging. Battery companies naturally do not want to fall behind.

Author: Han Yongchang, Editors: Li Qin, Yang Xuan; Source: 36Kr Auto; Original Title "CATL, BYD Compete in Supercharging, Power Batteries Will Enter the 6C Era"