The “slowness” of the 46 series large cylindrical battery and the “speed” of the short knife battery
In the field of new energy batteries, the 46 series large cylindrical battery and the short knife battery represent two emerging forms of technical paths.
Recently, the 100 millionth 4680 battery and the short knife battery pack of Tesla have been offline, and the industrialization rhythm of the two major technical routes has once again become the focus of the industry. From the perspective of technological progress, the 4680 batteries currently offline by Tesla are mainly single-dry process (negative electrode uses dry electrode technology). To achieve its established target performance threshold, dual-dry electrode and full-ear technology processes need to be met at the same time.
According to news, Tesla will update four dual-dry 4680 batteries in 2026. This also means that it will take more than one year for the dual-dry 4680 battery to mature industrialization. On the market side, BMW, which once issued a sky-high order of 70 billion yuan for large cylindrical batteries, also “lay down its flag” due to its slow transformation to electrification, resulting in the overall installation progress of the 46 series large cylindrical battery being slower than expected. In contrast, the industrialization of the short-blade battery technology route is rapid. The significant trend in the industry is that more and more battery companies and OEMs have deployed short-blade batteries. Behind this trend, it also reflects the obvious advantages of short-blade batteries in battery form, technology, performance and industrialization.
The 46 series large cylindrical vehicle loading is not as expected
The reasons for the slow progress of the industrialization of the 46 series large battery are complex and multifaceted.
From Tesla’s firm technical route, on the one hand, the breakthrough of the dual dry electrode technology is the key bottleneck of its 4680 battery mass production. In particular, the positive electrode active material has high electrochemical activity, and chemical changes are prone to occur during the rolling process, which makes the uniformity and consistency of the positive electrode dry electrode film more difficult to control, hindering its rapid large-scale mass production. On the other hand, while the full-ear design brings many advantages, it also increases the difficulty of ear welding. From spot welding to full-ear surface welding, the welding process and welding volume have increased significantly, the laser intensity and focal length are not easy to control, and it is easy to weld through the battery cell or not fully welded. Affected by multiple technical difficulties, Tesla’s 4680 battery failed to reach its set goals in 2023 in terms of performance and production capacity. This also directly led to the multiple delays of Tesla’s planned “$25,000 electric car”.
According to foreign media reports, the yield of Tesla’s dual-dry method positive electrode test production line is only 20%-30%, but the goal of achieving a 90% yield in H1 2025, supporting the dual-dry method 4680 mass-produced Cybertruck, and a weekly output of 2-3k vehicles has not changed. To this end, Tesla also plans to move the dual-dry method 4680 production line to a larger, upgraded Austin, Texas factory. Although Tesla’s 4680 dual-dry method large cylinder has initially achieved small-scale production, it will take some time to expand the scale while ensuring quality and yield. At the same time, due to the difficulty of improving the process, yield and performance, large cylindrical batteries have not yet shown competitive advantages in cost and performance. Looking at global car companies, the current demand for the installation of 46 series large cylindrical batteries is still relatively limited. It is worth noting that compared with Tesla’s continued heavy bet on 4680 power, the domestic exploration of the application of large cylindrical batteries in non-power fields is very active. Under the differentiation and refinement of terminal demand perception, application scenarios and technical route selection by overseas and domestic large cylindrical battery companies, the 46 series large cylindrical batteries will also go out of the industrialization process of different tracks and different rhythms.
Short knife battery market “advances”
As a new generation of products parallel to the 46 series large cylindrical technology route, the industrialization process of short knife batteries is in full swing. In recent years, more and more battery factories and OEMs have begun to deploy and apply the short knife battery technology route, and regard it as one of the mainstream product technology directions in the future. Starting from the underlying logic of energy storage systems and scenario applications, combined with the forward deduction of safety, system integration, grouping efficiency, cost reduction and other dimensions, it is believed that the L500 short knife energy storage cell with a length of 500mm and a height of 215mm based on the stacking process is the optimal solution for a 20-foot energy storage cabin.
Summary: Overall, the rise of the industrialization of 4680 large cylindrical batteries and short-blade batteries will inevitably lead to changes in the power and energy storage battery industry. Tesla’s brand influence and technical strength provide opportunities for the development of 4680 batteries. In the long run, 4680 batteries are still expected to gain a larger market share in the future. The strong momentum of short-blade batteries in technology upgrades and market competition also indicates that the industrialization opportunities of short-blade batteries will develop faster and more rapidly.
