15 minutes of driving range of 500+km, dismantling the world's most powerful lithium iron phosphate fast-charging battery

Although new energy vehicles have accounted for more than one-third of the market share, concerns about battery life and energy replenishment are still restricting the development of the industry and affecting users' travel experience.

The source of the problem lies in batteries. Among the two major technical routes of passenger car batteries, lithium iron phosphate batteries are highly safe and low in cost, but have poor energy density and fast charging capabilities, while ternary lithium batteries are just the opposite.

This has led to a clear distinction between the two battery technologies for a long time: ternary lithium batteries are mainly installed in high-end models to ensure battery life and experience; lithium iron phosphate batteries are installed in mid- and low-end models to ensure cost-effectiveness.

In order to combine the advantages of the two, the industry has made many attempts to use lithium iron phosphate batteries as the base. For example, BYD's blade battery improves battery life by improving battery technology and body chassis integrated CTB technology, and then Honeycomb Energy's short blade battery further optimizes the structure. Currently, the most eye-catching data in the industry is the latest Shenxing battery released by CATL, which has a range of 400km in 15 minutes, but this has not reached the limit of lithium iron phosphate batteries.

On December 14, Zeekr Intelligent Technology released its self-developed BRIC battery, which further improved the fast charging efficiency of lithium iron phosphate batteries and can run 500+km after charging for 15 minutes.

With the fast charging experience brought by the 800V high-voltage platform and the "1515 Convenient Electricity" layout of the JiChong Network, Zeekr is building an ecological moat for electric travel.

15 minutes of driving range 500+km

Among users' energy replenishment concerns, battery life and fast charging are the most important. Under the premise of low cost of lithium iron phosphate, BRICS Battery has made major breakthroughs in these two aspects.

The battery pack is composed of multiple battery cells. In order to improve battery life, a conventional method is to increase the number of battery cells. However, the volume of the battery pack is limited by the vehicle chassis. To fit more battery cells in a small space, the first thing to solve is to solve the problem of battery pack space utilization.

Let's take a look at the statistics on battery pack utilization in the industry: the volume utilization of 4680 batteries is 63%; the volume utilization of ordinary lithium iron phosphate batteries is 66%; the ceiling of ternary lithium batteries, the volume utilization rate has just exceeded 72%. The highest volume utilization rate of Zeekr gold brick batteries has reached an abnormal 83.7%, making it the power battery with the highest volume utilization rate in the world.

The battery cells are installed in the physical structural parts of the battery, and the way to improve the utilization rate is also very simple, that is, to modify the battery pack structural parts. Zeekr uses an integrated liquid cooling tray at the bottom of the battery to replace the traditional water pipe structure to reduce the squeeze of the structural parts on the battery cell space; adopts a "compact sandwich structure" of battery cells, upper covers, and bottom plates to release the vertical space of the battery cell compartment; aviation-grade ultra-thin thermal barrier materials are used between the battery cells to fully improve the volume utilization rate. Compared with traditional designs, the total length of the BRICS battery sampling line has also been shortened by 157 m, the number of core components has been reduced by 35%, and the battery mass energy density has also increased by more than 10%.

According to Zeekr's calculations, the integrated liquid cooling tray and "compact sandwich structure" used at the bottom of the battery and the three items of Superb Materials increase the battery space volume utilization by 8.5%, 7.6%, and 6% respectively.

Logically, there is no overly complicated assumption, but it involves a series of issues such as battery heat dissipation, fixation, and the use of new materials. It is very difficult to operate and is a typical problem of being easier said than done.

Another major advantage of the BRICS battery is its efficient energy replenishment. In the 10% to 80% fast charging range, it can achieve a 15-minute charge and increase the driving range by more than 500 km. It is the world's fastest mass-produced lithium iron phosphate battery.

In order to achieve this effect, Zeekr has made many technological innovations. For example, in terms of battery cell structure, the electrodes of the BRIC battery adopt a stacked multi-pole ear structure design. Under ultra-fast charging conditions, the heat distribution is more uniform and the temperature control is more efficient. The BRIC battery also adopts a double-rivet pole guide design, and its current capacity is increased by 100% compared to the single-pole solution. In addition to structural innovation, Zeekr also uses lithium-ion full-process acceleration technology to improve the overall efficiency of lithium-ion release, transmission, and reception, thereby achieving stable and efficient charging performance under high voltage and high current.

Fast charging requires an 800V high-voltage platform as the underlying technical support. Under the unified 800V architecture and ultra-high charging technology, the maximum charging power of the BRICS battery can reach 500 kW and the maximum charging rate can reach 4.5C;

In order to ensure higher energy replenishment efficiency, Zeekr completed the technical layout of the charging pile in advance.

According to Xie Shibin, vice president of Zeekr, the charging pile has evolved into three generations, with power levels of 360kW, 600kW, and 800kW respectively, and the charging pile is basically ahead of the vehicle.

"Our 800V charging pile has been waiting for 800V cars for two years."

Lin Jinwen, vice president of Zeekr, said that although 800V was only mentioned frequently in the industry during this year's Shanghai Auto Show, Zeekr had already laid the foundation for the 800V-compatible Jichong V1 charging pile two years ago. Jichong is the first charging network in China that has 800V platform high-voltage ultra-fast charging capabilities.

Zeekr believes that 5C, 6C and even 7C battery technologies may appear in the future, but for safety reasons, the charging voltage cannot be increased indefinitely. An 800kW charging pile is fully capable of supporting the charging of 6C batteries, and the third-generation charging pile is Zeekr's early move in this regard.

Many OEMs make battery PACKs, but relatively few develop their own battery cells. An Conghui also explained why Zeekr wants to develop its own batteries.

"Zeekr believes that if a smart electric vehicle company wants to be competitive in the future, batteries are the core and most basic element. This is also one of the moats for Zeekr's future development." Zeekr CEO An Conghui believes that batteries are the foundation of electric vehicles. Whether batteries, motors or electronic controls, including gearboxes, electric drive systems and batteries are the foundation of electric vehicles. This is Zeekr's understanding of batteries and its definition of their importance.

Zeekr's idea is to use battery technology as a starting point, combined with an 800V high-voltage platform and a super-charging network, to provide users with the ultimate smart travel experience and build their own moat.

"1515 Convenient Electricity" Plan

More efficient charging requires the two-way evolution of high battery charging rates and ultra-fast charging facilities. Based on this logic, Zeekr proposed the "1515 Convenient Electricity" charging and energy replenishment strategy, which means finding a station in 15 minutes and charging in 15 minutes, making charging as convenient as going to a convenience store. In the next three years, "1515 Convenient Electricity" will cover more than 90% of Zeekr car owners, and will be infinitely close to 100%.

Zeekr has deployed a "1515 convenient electricity" charging network in urban areas; in inter-city cooperation with 35 domestic public operators, Zeekr's charging map has accumulated more than 610,000 high-quality third-party charging guns. In 2024, Zeekr's highway charging gun coverage rate will increase to more than 95%.

The UltraCharge network is the result of Zeekr's trials. When planning the energy replenishment strategy at the beginning, Zeekr provided three routes: UltraCharge Station, SuperCharge Station and LightCharge Station. However, the actual test results show that users are most satisfied with UltraCharge, so starting from 2022, Zeekr will focus on the comprehensive layout of the UltraCharge network.

According to Zeekr, after years of exploration, the Jichong Network has already possessed three very obvious advantages: a full-process intelligent charging system, intelligent power sharing technology, and a more reasonable layout.

Zeekr integrates the whole process of intelligent charging system into the car system. From finding a station to finishing charging, the whole process of charging, including battery preheating, intelligent pile search, and intelligent lock reduction, is 100% mobile-free.

In real life, charging in winter is a typical usage scenario. The smart charging mode will preheat the battery while the car is navigating to charge, thereby shortening the charging time. This function will be gradually pushed starting from OS 5.1.

Intelligent power sharing technology is also a major advantage of the super charging station. It can intelligently distribute power in real time according to the power supply of each charging vehicle, maximize the use of the power pool, and allow each charging pile in the super charging station to be super fast. Let's make a simple assumption. If the four piles of a super charging pile are working at the same time, when piles 1 and 2 are almost full, their power will be "subsidized" to piles 3 and 4 that have just started charging.