The Battle for Lithium Battery Welding Supremacy: Korolweld\'s Multi-Layer Tab Welding Technology Takes the Lead

In today's rapidly evolving new energy sector, every breakthrough in lithium battery technology sends ripples throughout the entire industry. From enhancing energy density to reducing production costs, from improving safety to extending service life, the industry continues pushing the boundaries of battery performance.

Among the myriad of new materials and technologies, composite current collectors represent one of the most promising lithium battery materials, offering significant advantages in both cost and performance. With the acceleration of solid-state battery industrialization, their application prospects are becoming increasingly promising.

Behind the visible progress of composite current collectors lies a company that has solved critical welding process bottlenecks, enabling large-scale commercial production. OFweek Lithium Battery has observed that the leading enterprise in composite current collector welding is not a traditional lithium battery equipment giant, but Korolweld, established in 2023!

source: Korolweld

Comparative Analysis of Various Welding Technologies

In lithium battery or battery pack manufacturing, over 20 processes involve welding to achieve conductive connections or sealing. Among these, multi-layer tab welding represents the "Mount Everest" of lithium battery manufacturing welding processes, once creating significant bottlenecks for the entire lithium battery industry chain.

Traditional welding processes number over ten types, with resistance welding, laser welding, and ultrasonic welding being the most widely recognized. These three welding technologies each have distinct strengths and limitations.

Traditional current collector welding methods typically involve three or two steps. The three-step process includes multi-layer tab pre-welding (ultrasonic), multi-layer tab final welding (laser), and tab-to-pole welding (laser). The two-step process adds the pole during multi-layer tab pre-welding, followed by laser final welding.

In essence, traditional multi-layer tab welding processes require mountain climbers to alternately use ice axes and ropes—ultrasonic welding completes pre-welding, then laser welding must perform final welding reinforcement. Multiple processes not only create efficiency losses but also leave microscopic vulnerabilities.

In composite current collector welding scenarios, the greater challenge lies in simultaneously conquering three "technical peaks": molten pool control of ultra-thin foils, interface bonding strength of hundred-layer stacks, and thermal deformation suppression during welding.

An industry insider noted, "Common welding processes result in lengthy cell welding workflows, multiple welding stations, low efficiency coupled with unstable welding yields, and high equipment investment costs. This constrains composite current collector development, and common welding processes make large-scale production of composite current collectors particularly challenging."

Single-Pass Multi-Layer Tab Welding

Established in March 2023, Korolweld has optimized resistance welding and integrated the advantages of ultrasonic and laser welding in multi-layer tab welding, launching a revolutionary composite current collector welding solution—pressure fusion welding.

Korolweld has technologically eliminated the spattering phenomenon in resistance welding, enabling this operationally simple, automation-friendly traditional process to be applied to multi-layer tab welding and composite current collector welding. Additionally, Korolweld leverages resistance welding's atomic-level bonding advantages to completely solve weld point conductivity issues while achieving linear and circular connections.

After overcoming resistance welding's greatest challenges in multi-layer tab and composite current collector welding applications, pressure fusion welding—with its high-temperature, high-pressure process characteristics and integration of ultrasonic and laser welding qualities—can achieve single-pass welding of multi-layer tabs and tab-to-pole connections.

Single-pass completion of multi-layer tab welding that traditionally requires two or more passes represents pressure fusion welding's first key advantage; capability for composite current collector welding represents its second key advantage.

Since pressure fusion welding's introduction to the lithium battery industry, it has attracted close attention from leading battery manufacturers because pressure fusion welding's process methodology, economics, and manufacturability all demonstrate significant improvements and clear advantages over traditional welding processes.

According to OFweek Lithium Battery's research, in multi-layer tab welding processes, Korolweld's pressure fusion welding achieves welding times under 1 second, breakthrough performance exceeding 200-layer tab welding, with application cases demonstrating stable 160-layer tab-to-pole single-step welding at yields exceeding 99.9%. For composite copper foil welding, it achieves single-step welding of over 100 layers of tabs and poles.

Pressure fusion welding equipment costs 40% less than traditional processes; single equipment efficiency reaches 10PPM; high repeatability with configurable monitoring systems; low power consumption with electricity costs under 0.002 yuan per weld point...

Korolweld released its next-generation tab-to-pole welding workstation in H1 2025 and plans to launch its next-generation composite current collector welding workstation in H2 2025.

Currently, Korolweld's pressure fusion welding has passed testing by virtually all renowned lithium battery manufacturers, with some leading clients achieving production line deliveries.

Synergy with Composite Current Collectors

Indeed, solving multi-layer tab welding and composite current collector welding challenges represents not only a technological revolution in lithium battery manufacturing welding processes but also brings transformative change to the entire lithium battery industry. This begins with composite current collectors.

In traditional lithium batteries, indispensable current collectors account for approximately 13% of battery costs and 18% of battery weight.

Traditional current collectors are relatively thick, heavy, and require substantial metal materials. They also face limitations in tensile strength and ductility, factors that not only impact lithium battery energy density and range but also prevent further production cost reductions.

Current collectors require copper (copper foil for negative electrode current collectors). Sustained copper price increases have created enormous pressure for lithium battery cost control. As of July 30, 2025, copper spot prices reached 79,000 yuan/ton, showing volatile upward trends over five years.

To overcome traditional current collector limitations, composite current collectors emerged. Composite current collectors represent a new type of current collector material that, unlike traditional lithium battery current collectors using pure copper/aluminum foils, adopts a "metal-polymer substrate-metal" sandwich structure.

Composite current collector core structures include PET/PP/PI and other polymer materials as intermediate substrate films, with aluminum/copper conductive layers deposited on both sides through magnetron sputtering, vacuum evaporation, electroplating, and other processes.

Composite current collectors' "hardcore" advantages include:

Reduced Battery Manufacturing Costs: Raw material costs can decrease by over 50% compared to traditional foils.

Enhanced Battery Safety: Conventional current collector materials produce large burrs when punctured, causing internal short circuits and battery thermal runaway. Composite current collector materials produce smaller burrs when punctured, and polymer material layers melt during battery short circuits or punctures, creating a "point break" effect that controls short-circuit current increases, effectively managing battery thermal runaway.

Weight Reduction and Energy Density Enhancement: Composite current collectors use polymer materials to replace over 60% of metals, significantly reducing weight and increasing battery energy density by 5%-10%.

Extended Battery Cycle Life: Compared to traditional current collectors, composite current collectors reduce lithium dendrite penetration risks, reduce electrode sheet cracking or detachment, reduce electrolyte decomposition and side reactions, and reduce local polarization, extending battery cycle life by over 5%.

Solid-State Battery Compatibility: Solid-state batteries are better suited for composite current collectors, making composite current collector technological progress particularly crucial for solid-state battery industrialization.

As the most critical welding process in composite current collectors, Korolweld's pressure fusion welding undoubtedly facilitates composite current collector development, enabling higher-quality composite current collectors in lithium battery manufacturing.

Naturally, composite current collector applications represent only pressure fusion welding's most typical application scenario. Pressure fusion welding processes offer broad applications in power batteries, energy storage, electric two/three-wheelers, 3C consumer electronics, drones, and other fields.

According to industry sources, CALB's industry-leading "Extreme Simplicity Manufacturing" One-Stop technology utilizes Korolweld's pressure fusion welding for welding applications.

Additionally, companies including BYD's FinDreams Battery, Gotion High-Tech, Zhengli New Energy, SVOLT Energy, Sunwoda, Ruipu Lanjun in power battery and energy storage sectors; ATL, Xineng'an, COSMX, Leewei, Qingtao Development, Cubic Energy, and Jinyu Energy in 3C consumer sectors; and material companies like Yingbang Corporation, Jiangsu Zhuoli, and Baoming Technology are engaging with Korolweld's pressure fusion welding technology.

Conclusion

Korolweld's breakthrough validates a key principle: when industry chains experience intense competition, solving fundamental process bottlenecks often opens new blue ocean opportunities.

As composite current collector technology commercialization accelerates, pressure fusion welding's performance in gold-silver composite layer welding becomes even more anticipated. This young company, established less than three years ago, is using hardcore process innovation to prove that smart manufacturing's value lies not only in scale advantages but in the ability to solve real global industry challenges.