Cell & Pack Manufacturing

Stacking Versus Winding Strength

Weakness

Opportunity

Threat

Applications

Higher energy density and thermal management due to lower internal resistance.

Slower production speed due to precision layer alignment & index motion.

Less prone to swelling & core collapse.

Higher costs due to complex manufacturing equipment.

Rising demand for EVs and stationary energy storage systems highlights stacking's high-density benefits.

Competing technologies like hybrid stacking-winding techniques may reduce its exclusivity in precision.

Customizable for unique form factors, like EVs & aerospace.

Limited scalability in high-volume production.

Fastest growing solution with companies like BYD Blade battery) and Apple adopting it for high C-rate applications (due to lower internal resistance)

Stacking involves stacking electrodes and separators into precise layers that are atop one another to form a flat cell. These can be separate cut layers or one continuous electrode as well. This process enables high energy density and precise structural stability, making it ideal for applications requiring compact, high-performance batteries, such as electric vehicles EVs and aerospace systems. Winding, or the jelly-roll process, involves rolling electrodes and separators into a cylindrical or prismatic structure. It is widely adopted due to its speed and scalability, making it suitable for mass production in consumer electronics and power tools.

Stacking

HOW ARE THE TWO TECHNIQUES DIFFERENT?

Recent innovations include hybrid techniques like laminated winding and Z stacking, which combines stacking and winding to optimize energy density while maintaining manufacturing efficiency.

Winding

Automation in stacking processes has also improved production speeds, closing the gap with winding techniques.

Improved packing efficiency for rectangular modules, maximizing volume utilization in packs.

Potential failure (burrs, delamination, etc.) due to additional cutting required.

Mature, well-established technology with lower production costs.

Slightly lower energy density due to voids at edges of rolled layers.

High production speed and scalability, ideal for mass production.

Packing efficiency is lower for rectangular or prismatic packs due to cylindrical shapes. Prone to localized hotspots during high discharge rates.

Advances in automation and robotics are making stacking more cost-competitive.

Popularity in passenger & commercial EVs and consumer electronics at low cost supports growth. Innovations in thermal management solutions such as shutdown separators could address limitations in heat dissipation.

Limited scalability compared to winding could deter adoption in mass markets.

Emerging battery formats, such as solid-state cells, could demand new manufacturing paradigms.

Most stable technology with companies like CATL & Tesla and commercial high volume manufacturers are widely utilizing this technique due to its scalability and lower cost.

a) Winding; b) Stacking Sources: Tycorun, Bonnen Batteries, Evaluating the Manufacturing Quality of Lithium Ion Pouch Batteries

Extracted from the PDF; charts and images may read imperfectly.