On February 23rd, 2023, HiNa Battery presented three types of Na-ion battery cells at the new product launch. What is even more interesting is that HiNa Battery has launched the first Na-ion battery electric vehicle in cooperation with JAC Motors. This Na-ion battery system has a capacity of 25kWh and an energy density of 140Wh/kg for the cells, while the system energy density is 120Wh/kg and supports fast charging from 3C to 4C.     This time, HiNa Battery's Na-ion battery was installed in the electric vehicle, proving that Na-ion battery is not only a mixed A/B battery system with lithium-ion battery, but can be installed in electric vehicles independently. This Na-ion battery system is installed in JAC Motors's Sihao EX10 Flower Fairy, an A00-class model to be launched by the end of 2021. The sodium ion battery system version is equipped with a battery capacity of 25kWh Na-ion battery, the CLTC battery endurance range of 252 km, the energy density of the Na-ion battery system is about 120Wh/kg. As a reference, the lithium-ion battery system version is equipped with a battery capacity of 30.2kWh LFP battery, the CLTC battery endurance range of 301 km, the energy density of the LFP battery system is about 140Wh/kg.     Sihao EX10 Flower Fairy (Na-ion battery version) Manufacturer JAC Motors Level A00-class Mini EV Energy type BEV Current Status Prototype EV CLTC battery endurance range 252km Maximum speed 120km/h Acceleration time ≤5.5s (From 0 to 50km/h) Max. climbing degree 25% Body structure 4-door, 5-seater Wheelbase 2390mm Length*width*height 3650*1670*1540mm Vehicle weight 1130kg EV battery system Battery Type Na-ion battery Cell Type Cylindrical cell Cell capacity 12Ah Cell weight 256g Cell energy density ≥140Wh/kg Battery pack into groups 6P110S Battery system capacity 25kWh Battery system capacity 72Ah Battery system voltage 341V Battery system energy density 120Wh/kg Capacity retention at -20℃ ≥90% Fast charging time 15min (From 30%SOC to 80%SOC) 20min (From 10%SOC to 80%SOC) Motor System Motor type Permanent magnet synchronous motor Maximum power 45KW Motor torque ≤150N.m   In terms of fast charging performance, Na-ion battery and LFP battery are about the same. However, in terms of EV battery system capacity and energy density, Na-ion batteries are still inferior to LFP batteries. Does this mean that Na-ion batteries are not valuable in electric vehicle application scenarios? Of course not. There are three reasons. First, the battery system energy density of 120 Wh/kg of EV battery system itself has reached the threshold for installation in small miniature electric vehicles. Some of the current small mini electric vehicles are similar. For example, the battery system energy density of Dfsk Motor's Fengguang MiniEV is only 120 Wh/kg, and the battery system energy density of Mercedes-Benz's EQC is only 125 Wh/kg. Secondly, the Na-ion battery cell used in the Sihao EX10 Flower Fairy is not one of the...

In the past two years, FinDreams Battery (BYD), SVOLT Energy, EVE, CALB, Sunwoda and other battery cell manufacturers are using electrode stacking process for prismatic cell products on a large scale, "electrode stacking process & long thin size blade cells" has become the mainstream of the trend of prismatic cells. In fact, with the popularity of electric vehicles, battery cells are being designed in larger and larger sizes to meet endurance, safety, lifespan and cost requirements. In this case, the shortcomings of the electrode winding process are magnified, such as the inevitable large bending deformation of the coating material on the electrode, which leads to the formation of dropped material and dead zones at the bend. Also, during the electrode winding process, the tension on the electrode sheet and the battery separator is easily uneven, resulting in wrinkles and poor alignment. Compared with the electrode winding process, the electrode stacking process is more suitable for large prismatic cells, and the advantages are beginning to emerge. For more details, please click “Features of Lamination & Stacking Process for Lithium-ion Battery Cells” to browse. Picture 1. Duplex-station Battery Cell Stacking Machine SVOLT Energy, founded only five years ago, is in the TOP 10 of installed global EV battery capacity in both 2021 and the first half of 2022. Such a proud achievement is largely based on its strong battery technology innovation capability, especially the innovation and continuous upgrade evolution of electrode stacking process technology and electrode stacking manufacturing technology. The stacking efficiency of the first generation of electrode stacking technology is 0.6 sec/layer, the second generation is 0.45 sec/layer, while the third generation of "Fly Stacking", with an efficiency of 0.125 sec/layer, has rivaled or even surpassed the electrode winding process, and is in the absolute leading position in the track of stacked cells. The core technology of "Fly Stacking" that allows SVOLT Energy to significantly improve stacking efficiency is the shift from "single electrode cutting and stacking" to "multiple electrodes cutting and stacking". Multiple electrodes are cut and stacked at the same time on one machine to achieve more efficient output and double the efficiency with almost no change in the cost of a single machine. In addition, the third generation of "Fly Stacking" technology also integrates battery electrode unwinding, cutting, hot pressing, CCD online monitoring and HI-POT online monitoring to achieve full inspection of all single electrodes. Picture 2. SVOLT Energy Fly Stacking Machine Thanks to the continued innovation and application of top battery cell manufacturers in the electrode stacking process for prismatic cells, the electrode stacking process is expected to be used on a large scale in prismatic cells in the future and to overtake the electrode winding process to become mainstream. WinAck G...

In the next 2~3 years, ESS battery cells will continue to upgrade to higher capacity, the cell capacity is expected to increase to more than 300Ah, which will put higher requirements on battery technology, production and materials. For now, these ESS large battery cells are prismatic cells. According to the difference of cell assembly process, prismatic cells can be divided into two categories: stacked battery cells and wound battery cells. So, what is the difference between stacked battery cells and wound battery cells？The following is battery electrode lamination & stacking process VS battery electrode winding process, showing the advantages and disadvantages of each. The battery winding process has been developed over a long period of time and has the following advantages. The industry chain supporting the battery winding process is very mature and the investment cost is relatively smaller. Battery electrode winding technology is very mature, the battery electrode winding machine has been highly automated, and its production efficiency and yield rate are also very high. As the cell capacity and size continue to increase, the disadvantages of the battery winding process become more apparent. Wound cells have curvature at the corners, resulting in lower space utilization than stacked cells, and the larger the battery capacity, the more obvious the space waste. Wound cells have curvature at the C-corners, and the cell is prone to wavy deformation, which will lead to poor battery interface and uneven current distribution, accelerating the decay of battery life. After the bending of the electrodes of the wound cells, the coating material undergoes large bending deformation, which will easily induce problems such as powder dropping and burring, and this will increase the risk of internal short circuit and thermal runaway of the battery. As the cell capacity and size continue to increase, the requirements of wound battery cells for battery manufacturers' extreme manufacturing will rapidly increase, and the difficulty of compatibility between high-capacity battery cells and the winding process will steeply increase. Below are the features of the battery lamination & stacking process. Firstly, the advantages. The number of battery tabs in stacked cells is twice that of wound cells. The increase in the number of battery tabs results in shorter electron transfer distance, 10%~15% lower resistance compared to wound cells, less heat generation, and longer theoretical cycle life, meeting the requirements of mass ESS for high safety and ultra-long cycle life. Stacked cells do not have the problem of C-corners in the process of cell assembly, which can make full use of the space at the corners of the battery shell and improve the volumetric energy density and mass energy density. The stacked cell does not have the problem of unbalanced internal stress in the C-corners, and each layer of electrodes can maintain a relatively flat interface during long-t...