Four trends in the development of energy storage cells

 

 

At present, China has become the main supply area of global energy storage batteries, and Chinese enterprises have become the mainstay of global energy storage batteries.

It is worth mentioning that the industry participants are mainly power battery factories, CATL and BYD are in the leading position, and the head effect of the industry is obvious. The echelon of energy storage cells is accelerating, and there are many new growth companies entering the market.

 

In addition to speeding up the global competitive landscape of card slots, the battery capacity is iterating from 280Ah to 300Ah or even higher. In addition, based on the application scenarios of energy storage, the energy storage cells are still seeing the cycle number, size, manufacturing process, etc., and the special batteries based on the application scenarios of energy storage are coming soon.

1. Increased capacity, competition in mass production

EVE has released a 560Ah energy storage battery - LF560K since last year. The battery capacity is 560Ah, twice that of LF280K, and the energy of a single battery reaches 1.792kWh. It is known as the energy storage battery with the largest capacity so far. In addition to EVE, HITHIUM, Envision AESC, Great Power, REPT, GOTION HIGH-TECH, BYD, Narada and other top 10 energy storage battery cell companies have successively released 300Ah and above capacity battery products.

While the capacity is increasing, mass production and delivery of 300Ah and above capacity batteries have also started. It is worth mentioning that Envision AESC has achieved mass production and delivery of 305Ah energy storage cells in the past two years, and recently released 315Ah energy storage cells.

At the beginning of this year, EVE's mass production of LF560K energy storage "super factory" in Jingmen, Hubei officially started construction, with an annual production capacity of 60GWh and an investment of 10.8 billion RMB.

Increased capacity, competition in mass production

 

In addition, LF 560k super factories have been built in Yunnan, Qinghai and other places. It is expected to start global delivery in Q2 of 2024. It is planned to achieve a production capacity of 100GWh of energy storage batteries in 2025. In addition to mass production of energy storage and large-capacity batteries, many manufacturers have made breakthroughs in battery performance.

The Envision AESC315Ah product has an energy density of 11% higher than that of the previous generation product on the basis of the same size, achieving "one kilowatt-hour of electricity for a single cell". At the same time, the cycle life is as high as 12,000 times, which meets the safe and reliable operation requirements of charging and discharging once a day for 25 years.

HITHIUM 320Ah is a new generation of special battery for power energy storage, which is more suitable for the application and development model of the power energy storage market in terms of cell cost, system cost, and standard configuration of the whole box.

Great Power 320Ah energy storage battery cell, compared with the previous generation of battery cell products, the single capacity has increased by 14%, and the system energy has increased by 14% in products of the same size. Its cycle life is >8000 times, and its service life exceeds 20 years. At the same time, it is excellent in low temperature capability, which can meet the requirements of storage at -40°C and discharge at -30°C.

2. Energy storage cell stacking vs winding comparison

The stacking process accelerates the penetration of batteries with a capacity of 300Ah and above. For example, the LF560K stacked cell launched by EVE. The 375Ah large-capacity energy storage battery launched by Higee adopts a stacking winding process. Narada's 305Ah energy storage battery uses a four-roll core stacking process.

Energy storage cell stacking vs winding comparison

 

According to reports, EVE 3.0 stacking technology can achieve a stacking rate of 0.2S/PCS, and a single stacking equipment can produce 1.3GWh. This has led to the construction of a subsequent energy storage battery super factory, with a single-line production capacity of 10GWh and a total production capacity of 40GWh. Based on the core demands of energy storage products in terms of safer, longer cycle life, more stability, and lower cycle life costs, the SVOLT 325Ah energy storage battery is built with the flying stack technology and based on the short-cut cell structure.

From a technical analysis point of view, the number of tabs in the full die-cutting of the stacking technology is doubled, which can solve the problem of current collection of electronic conductance by stacking instead of winding. The length of the unipolar sheet is shortened by 100 times, and the total yield rate of cell production is increased by 3%. In addition, stacking technology can simplify the system, reduce the number of components in the pack, improve production efficiency, and improve battery integration.

However, there are also many manufacturers that use the winding process to produce batteries with a capacity of over 300Ah. The 320Ah winding process energy storage battery released by Great Power has made a breakthrough in the direction of battery upgrade. Great Power revealed that it has adopted an exclusive electrolyte design formula and process, which can effectively reduce the internal resistance of the film, and realize the simulation optimization of the tab structure, and increase the core space utilization rate by 1%.

It is foreseeable that based on the manufacturing process, stacked and wound batteries are forming a competitive trend for batteries with a capacity of more than 300Ah.

3. Discussion on the size of energy storage cells

It is worth mentioning that the current 300Ah and above capacity energy storage cells are not only different in capacity and manufacturing, but also in size.

Some are following the 280Ah size. For example, the 320Ah cell released by HITHIUM still uses the "71173" size of its 280Ah cell. The dimensions of square energy storage cells with a capacity ranging from 280Ah to 320Ah launched by Narada, Envision AESC, and Great Power are also close to this size.

Discussion on the size of energy storage cells

 

Others are free size. In addition to BYD blade batteries with large size differences, there are 300Ah batteries from GOTION HIGH-TECH and 375Ah batteries from Higee. According to the parameters released by Higee, the heat dissipation area of the product has increased by 106%, and there is no need for a liquid cooling design, and the traditional forced air cooling can meet the needs of use.

Industry insiders pointed out that the unification of cell size is formed by market competition. For example, the large cylindrical battery in the power system is not achieved overnight. The reason why the battery sizes such as 21700 battery and 46 series can be formed is because it is selected by the market and formed through market competition.

However, battery cell manufacturers generally report that using 300Ah and larger capacity energy storage cells can upgrade a 20-foot liquid-cooled container to a 5MWh+ cabinet, reducing system costs by more than 10%. At the same time, the 5MWh+ cabinet can reduce the container volume of the system project by more than 10%.

4. Economy calls for long cycle of battery cells

The longer cycle life of energy storage batteries means lower cost of electricity in the whole life cycle. The data shows that when the cycle life of the energy storage battery increases to 10,000 times, the cost of energy storage will drop below 1,000 RMB/kWh, and the cost per unit of electricity will be less than 0.16 RMB after deducting charge and discharge losses and depreciation.

Economy calls for long cycle of battery cells

 

It is obvious that the increase in the service life of the battery can lead to a reduction in the cost of electricity in the entire life cycle of the energy storage system. It is precisely around the core needs of the market that top 10 energy storage lithium battery companies are investing more in the development of batteries with longer cycle life.

Many companies have developed energy storage batteries with a cycle life of 10,000 or even 12,000 times. Industry insiders analyzed that if the energy storage achieves a long cycle of 18,000 times, it can be used for 25 years in the case of two cycles a day, which is the same life as photovoltaics. Facing the fast-moving energy storage industry, greatly improving battery life has become an important development direction of the industry.

 

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