Since 2021, the global household energy storage scale has grown significantly, overseas, energy costs and electricity prices in Europe and the United States have continued to rise, superimposed by the Russia-Ukraine war and overseas large-scale power outages, especially in recent years, the frequent occurrence of extreme weather has increased the difficulty of energy supply, and the demand and cost of electricity for residents have increased significantly, and the household energy storage market has exploded beyond expectations. Domestically, with the widening of the peak-to-valley electricity price gap and the installation process of household distributed photovoltaics, household energy storage is expected to usher in an explosion. It is expected that the world will usher in a new stage of residential energy storage explosion in the next few years. On the other hand, the capacity of residential energy storage systems is iterating from 3-5 kWh to 5-20 kWh, which also puts forward new requirements for the capacity, power, cost and life of household energy storage batteries.
At present, the market should use consumer energy storage cells mainly including square, soft pack and cylindrical. At the cell capacity level, the capacity range is 50-100 Ah for square, 30-80 Ah for soft pack, and 10-50 Ah for cylindrical. Due to the diverse requirements for capacity and portability in household storage application scenarios, there are high requirements for flexible series and parallel connection of energy storage batteries. At present, the progress of large-scale application of large cylindrical batteries in the field of energy storage is significantly ahead of the power sector, especially in the household storage market penetration is outstanding, and many battery companies have launched or plan to launch large cylindrical household energy storage batteries. The product specifications of large cylindrical batteries released by Hichain Energy Storage cover 4680-46300, and the single capacity covers 10-50 Ah, which is more flexible and adaptable to meet the customized needs of household energy storage application scenarios. Penghui Energy also launched the 40135 series of large cylindrical batteries for the household energy storage market, which has been mass-produced and has received customer orders, 40135 large cylindrical batteries adopt all-tab structure, lithium iron phosphate low-temperature superconducting and full-cycle dynamic equilibrium technology, with super power, ultra-long battery life, wide temperature range and other excellent performance, mainly used in the field of household energy storage and portable energy storage, and is currently developing 46 series of large cylindrical batteries, which can be used in the field of household storage in the future.
There are many specifications of large cylindrical batteries, and the leading standard has not yet been formed, and the layout of enterprises has opportunities from 0 to 1. Different from ternary large cylindrical batteries, which are mostly 46 series in size, the models and specifications of the products of many companies in the residential energy storage market are slightly different. For example, the large cylindrical batteries produced by Penghui Energy and EVE are mainly 40135 models (40 mm diameter and 135 mm height), while the 4680-46300 large cylindrical batteries of Haichen Energy Storage are based on 46 mm diameter and cover 80-300 mm in height. The rest of the manufacturers have large cylindrical battery products with diameters ranging from 26-60 mm. At present, household batteries are in the early stage of development, and household storage products have rich application scenarios and need to adapt to the needs of products in different scenarios, so a unified standard has not yet been formed. Residential batteries are still in the early stage of development, companies are in the exploration stage, and in the future, new entrants can achieve corner overtaking through financing, product differentiation development, and sales channel broadening, and pay attention to the opportunities of household battery companies from 0 to 1. Combined with market demand and technology iteration, large cylinders are becoming a trend. Compared with the traditional small cylindrical battery, the large cylindrical battery has an increased size, the capacity of the single battery is higher, and the subsequent PACK composition is connected in series and parallel and the structural parts are reduced, which is conducive to reducing costs. Large cylindrical lithium iron phosphate batteries are favored by the household storage market, on the one hand, thanks to the optimization of manufacturing process and material system, the advantages of large cylindrical batteries in terms of cost, capacity, performance, cycle and safety are highlighted, and on the other hand, the innovative use of all-tab technology in the structure greatly improves the rate performance of battery charging and discharging.
The all-tab technology empowers lithium iron phosphate large cylindrical batteries, and the charging and discharging performance and safety are significantly improved. The traditional cylindrical battery tab is a guide wire welded at both ends of copper foil and aluminum foil, while the whole tab is to use the entire positive and negative current collectors as tabs, and connect the battery shell or battery cover plate with the current collector for a full area, which can greatly reduce the internal resistance and heat generation of the battery, thereby solving the heating problem of high energy density cells and increasing the peak power of charge and discharge. Taking the Tesla 4680 battery as an example, compared with the previous 2170 battery, the battery cell capacity is 5 times that of the 2170, and the charging power is increased by 6 times. At present, enterprises with this technology have also transplanted the technology to large cylindrical lithium iron phosphate batteries for household energy storage, such as EVE Lithium Energy and Penghui Energy's 40135 large cylindrical lithium iron phosphate batteries, which use all-tab tabs. The contact area of the tabs of the all-tab battery becomes larger, the welding area changes from line to surface, and the welding amount increases while the consistency requirements are higher, and the welding difficulty increases. It is expected that the large-scale application of large cylindrical batteries will give rise to the growth of welding demand, and it is recommended to pay attention to the leading domestic welding equipment, such as laser welding, ultrasonic rolling welding and other equipment manufacturers.
The cycle life of the large cylindrical battery aims for the threshold of 5000 times, breaking through to a higher goal. The cycle life of traditional cylindrical batteries is about 2000 times, and the service life is short and the cost is high. Service life as a key indicator of energy storage batteries, large cylindrical batteries are greatly improved compared with traditional cylindrical batteries, and some companies have aimed at 5,000 cycles or even higher cycles to achieve household storage products can meet the needs of 10 years or even longer. EVE's 40135 cylindrical battery has 4000 cycles. Hichain Energy Storage Large Cylindrical Battery 4680-46300 adopts GI system design, curvature tension coupling design, 3D1nfil boundary design, etc., to improve the electrochemical reaction environment of large cylindrical battery, with more than 5000 cycles.
The advantages of large cylindrical batteries in terms of cost, life, safety and subsequent matching are self-evident. At present, a number of battery companies have begun to focus on the layout of large cylindrical lithium iron phosphate batteries in response to the needs of household energy storage and portable energy storage application scenarios. In the future, as the product is gradually verified in terms of cost performance, safety and portability, it is expected that more companies will participate, and the volume of large cylindrical lithium iron phosphate batteries is expected to drive the "change" of the supply side of household batteries.
Source：https://mp.weixin.qq.com/s/PqAdUX-kfM7xfBr1xOTyhQ