Energy storage power station GWh "upgraded": Honeycomb short knife 325Ah underlying innovation "breakthrough"

In the first half of this year, my country's newly commissioned energy storage capacity was about 8.63GW/17.72GWh. One obvious change is that single GWh-level energy storage projects have increased, and the industry is looking for larger capacity energy storage cells to support power station operations.

As demand is transmitted upward, various battery companies are closely launching 300+Ah battery cells of different specifications, hoping to gradually replace 280Ah battery cells through all-round performance improvements such as longer cycle life and higher safety.

From the industry's perspective, the basic logic of upgrading and iterating energy storage cells is to achieve performance improvements through material innovation, structural optimization, etc. However, starting from the underlying innovation of the cell, it is very important to reshape the design language of the cell while taking into account performance improvements and ensuring its own safety.

How to redefine energy storage cells? Honeycomb 325Ah cells are made in this way:

With the L-shaped short blade structure as the core design language, the risk of temperature rise is reduced from the source in terms of safety; combined with the efficient flying stack manufacturing process, it helps to reduce costs and increase efficiency in battery cell production, closely adhering to the two main themes of energy storage safety and economy.

The honeycomb has given full play to the dual advantages of "short knife + flying stack", making the 325Ah battery cell have performance advantages such as high volume energy density of 165Wh/Kg, ultra-long cycle life of 12,000 times, and no fire or smoke in the needle puncture test, breaking the energy "impossible triangle" that cannot combine high energy density, long cycle life and high safety.

It is worth mentioning that on October 25, Honeycomb Energy's world's first 325Ah energy storage cell rolled off the production line at the Chengdu base. Just one week later, Honeycomb Energy announced that the 325Ah energy storage cell will be used in GCL Group's new "Xin+" series of energy storage system products, taking a substantial step towards the full-range short-cut energy storage.

Safety concerns with large-capacity battery cell upgrades

Under the standard of 20-foot container, the capacity of energy storage system is increased, which has the effect of "increasing revenue and reducing expenditure":

In terms of open source, the energy density and cycle life of single large-capacity system products are further improved, which can increase the revenue of power stations; in terms of cost saving, a larger capacity system means fewer products are required for the project, which can reduce the land construction cost of the energy storage power station, and the comprehensive costs such as reduced construction workload, commissioning and operation and maintenance are effectively controlled.

The key to increasing the capacity of the energy storage system lies in increasing the capacity of the battery cell. However, as the capacity of the battery cell increases, it becomes more difficult to dissipate heat, and the problem of uneven heat distribution becomes more obvious, which can easily cause thermal runaway of the battery cell.

What's worse, the industry has proposed that "the explosion index of large-capacity iron-lithium batteries is twice that of ternary batteries." Therefore, safety issues have become the primary problem after the capacity of energy storage batteries is increased.

In order to solve the safety hazards brought about by the increase in capacity, Honeycomb Energy's 325Ah battery cell started from the bottom-up innovation and proposed a short knife structure design to solve the problem of uneven heat dissipation of large-capacity batteries from the source, and carried out a more profound re-architecting of safety.

Specifically, under the short knife battery cell design, the honeycomb 325Ah battery is thin, has fewer layers, a large surface area, and good heat dissipation. The temperature rise is within 5°C under 1C current; and the current capacity of the battery cell's poles, ears, and connectors is simulated and optimized. Compared with the LFP280Ah battery cell, its temperature distribution is more friendly to thermal management.

In addition, the increase in battery internal resistance also increases the risk of excessive temperature rise. In this regard, the honeycomb uses the flying stacking process to not only improve the safety impact of high internal resistance and deformation of the pole pieces of traditional VDA cells, but also further reduce the overall thickness of the cell, realizing "lengthening and thinning", which is more conducive to the heat dissipation of the cell.

In terms of actual enabling system integration, GCL Group has developed a new generation of liquid-cooled large PACK based on the honeycomb 325Ah battery cell design. It adopts a double-sided cooling design, and the temperature difference of a single battery cell is less than 2 degrees, realizing a more comprehensive thermal barrier design and achieving the effect of zero heat spread.

As the price war intensifies, how can cell cost reduction enable energy storage economics?

Once the safety issue is resolved, the economic benefits of energy storage will follow. Currently, the price war for energy storage is intensifying, and system quotations have been nearly halved. The industry is also plagued by concerns about overcapacity and insufficient utilization.

In terms of quotation, the energy storage system quotation has also fallen below 1 yuan/Wh, with the latest quotation reaching 0.74 yuan/Wh, which is nearly halved compared to 1.5 yuan/Wh at the beginning of the year. The phenomenon of "increased revenue but not increased profits" in energy storage projects will become more serious. The cost reduction of battery cells can be transmitted downward to the overall cost reduction of the system, thereby further improving the economic efficiency of energy storage projects.

In terms of production capacity, GGII data shows that domestic energy storage battery production capacity has exceeded 200GWh in the first half of the year, and the overall capacity utilization rate has dropped from 87% in 2022 to less than 50% in the first half of this year.

In this context, battery companies are more challenged to adopt a comprehensive layout of cost reduction and efficiency improvement to cope with the industry crisis. In this regard, Honeycomb Energy has effectively controlled production costs through the flying stacking process and extreme manufacturing, and has improved the utilization rate of production lines and capacity through the co-production of power and storage products.

At present, the honeycomb stacking process has evolved to the third generation, with an efficiency of 0.125s/piece. Combined with the pole piece thermal compound + multi-piece stacking technology, the single-piece efficiency is increased by 200%, the investment per GWh is saved by 53%, and the unit area of ​​equipment is saved by more than 45%, which greatly reduces the factory construction cost, energy consumption cost and labor cost.

Moreover, the flying stacking process can realize the complete compounding of the pole piece and the diaphragm, ensuring the consistency of the positive and negative electrode reaction interfaces. Compared with the late cycle fatigue of wound batteries, the flying stacked batteries have better interface stability and longer cycle life of up to 12,000 times, basically achieving the same life of photovoltaic and energy storage, further improving the service life and economic benefits of energy storage power stations.

Considering the comprehensive cost reduction of system integration, the liquid-cooled energy storage cabinet equipped with 325Ah energy storage cells can increase the system energy density by 50%, reduce the number of cluster-level components by 55%, and reduce the cluster-level assembly cost by 28% compared to the current mainstream 280Ah liquid-cooled energy storage cabinet products in the industry.

In addition, co-production of power batteries and energy storage batteries is also one of the advantages of Honeycomb Energy. Based on the development of platform-based production lines, Honeycomb Energy can fully coordinate the production of power batteries and energy storage batteries, thereby improving the utilization rate of production lines.

Honeycomb 325Ah market exploration: diversified development of power, industrial and commercial energy storage

In terms of the market, the Honeycomb 325Ah battery cell will mainly target GWh-level energy storage applications in the future, as well as diversified markets such as power energy storage, industrial and commercial energy storage, etc.

Gaogong Energy Storage observed that based on the evolution of 300+Ah large storage cells, system integration has begun to move towards 5MWh+ capacity simultaneously.

In cooperation with GCL Group, it uses the system integration product designed with honeycomb 325Ah battery cells to increase group efficiency by 30%, reduce electrical connectors by 50%, and achieve a single PACK capacity of 200kWh. GCL uses the 200kWh large PACK as the main design unit, and a single standard 20-foot integrated cabin can achieve a total energy storage capacity of 6MWh.

In terms of other cooperation, Honeycomb Energy has won wide recognition from domestic and foreign customers, and has completed the delivery and grid connection of large-scale energy storage projects in Guangdong, Jiangsu, Hebei, Xinjiang and other places in China, and has won energy storage orders of more than 20GWh in Europe.

In the industrial and commercial energy storage track, there is currently no established standard in the industry for its supporting battery cells, and there is a large degree of selectivity, which gives greater opportunities to energy storage batteries with large capacity, new forms, and new processes. Honeycomb Energy's 325Ah battery cell has a greater opportunity to enter the market.