Why Stacking is Overtaking Winding for High-Rate Batteries
If you follow battery technology, you've probably noticed a growing shift toward stacked lithium-ion cells, especially in high-power applications like drones, power tools, and electric vehicles. While wound cells have long dominated the industry, stacked cells are proving to be a better choice for high-rate performance.
Why? It all comes down to efficiency, heat management, and longevity. Let’s break it down.
The Challenge of High-Rate Discharge
High-rate batteries need to deliver a lot of power in a short time, which puts significant strain on their internal structure. If a battery’s design doesn’t efficiently handle this load, it can lead to:
Increased internal resistance → Wasted energy and lower efficiency
Uneven current flow → Hotspots that degrade performance
Thermal buildup → Higher temperatures, safety risks, and shorter lifespan
This is where stacking takes the lead over traditional winding methods.
Structural Advantages of Stacking Technology
1. Multi-Tab Design for Lower Internal Resistance
Unlike traditional winding, stacking technology divides the positive and negative electrode sheets into multiple smaller sections, stacking them in parallel. This significantly increases the number of electrode tabs—typically more than twice that of wound cells. By shortening the ion transport path and reducing uneven current distribution, this design effectively lowers internal resistance by 10–15% compared to wound cells.
2. More Uniform Current Distribution
In wound cells, the single-tab design often leads to current concentration at the electrode edges, increasing localized polarization and reducing discharge efficiency. In contrast, stacked cells utilize a parallel structure, ensuring that current flows evenly across the entire electrode surface. This minimizes voltage drops during high-rate discharge and enhances power stability.
How Stacking Outperforms Winding
Lower Internal Resistance – One of the biggest advantages of stacking technology is its multi-tab parallel design, which significantly reduces internal resistance. In contrast, wound cells use a single-tab structure, forcing current to travel longer distances and increasing resistance. Lower resistance in stacked cells means more efficient power delivery, less energy loss, and better high-rate performance—a crucial factor for applications requiring rapid power output.
Higher Energy Density –Space utilization is critical in battery design, as it directly impacts energy density. Stacked batteries optimize internal space, achieving up to 95% space utilization, while wound batteries only reach around 88% due to their cylindrical or rolled structure. This means stacked cells can store more energy in the same volume, making them ideal for large-format, high-energy applications such as electric vehicles and energy storage systems.
Better Thermal Management – Heat dissipation is a major concern in high-power batteries, as localized overheating can accelerate degradation and pose safety risks. Wound cells tend to trap heat in the core, creating temperature gradients that can exceed 10°C, increasing the likelihood of thermal runaway. Stacked cells, however, dissipate heat more evenly, maintaining a temperature variation of less than 3°C, reducing thermal stress and enhancing battery lifespan.
More Versatile Applications – With lower resistance, higher energy density, and better heat management, stacked batteries are ideal for high-power applications like EVs, power tools, and aerospace. In contrast, wound batteries suit compact consumer electronics, where cost and manufacturing speed take priority over peak performance.
The Industry is Making the Shift
The demand for larger, high-performance batteries is driving innovation, and stacking technology is evolving to meet production challenges. Leading manufacturers are already rolling out faster, high-precision stacking methods, reducing production costs and making this technology more viable.
By 2027, the stacked cell market is expected to experience substantial growth, driven by increasing demand for high-performance batteries. This trend underscores the industry's shift towards more efficient and advanced energy storage solutions.
Stacking: The Future of High-Rate Batteries
Stacking technology is rapidly becoming the go-to choice for high-rate lithium-ion batteries, offering lower resistance, better heat management, and reduced mechanical stress. With the growing demand for high-power applications, stacked cells are on track to become the industry standard—it's not a matter of if, but when.