Technology
Technology
Rolled-Ribbon technology solves the longstanding industry problems associated with conventional cells (cylindrical, pouch and prismatic) for high-power high-capacity Li-ion applications. Conventional cells do not scale up well for increasing power and capacity. As battery systems power and capacity requirements increase; significant power and thermal issues emerge. These issues are difficult to solve and result in decreased battery system performance and increased battery system cost.
Rolled-Ribbon overcomes these problems. In tests that compare Rolled-Ribbon to conventional cells on a side-by-side basis using identical electrochemical formulations, Rolled-Ribbon cells outperform the conventional cells by wide margins. The Rolled-Ribbon advantage comes from its physical structure and is obtained independent of electrochemistry.
Rolled-Ribbon cells have both low impedance and low thermal resistance. This combination translates into:
Maximum Power Delivery - Charging and Discharging
Minimum Heat Generation
Maximum Energy Conversion Efficiency
Unparalleled Thermal Performance
Maximum Cell Cycle Life
And the benefits of Rolled-Ribbon technology don’t end here. The unique structure of Rolled-Ribbon cells enables these virtuous properties to be extended through the construction of batteries using Rolled-Ribbon’s unique Stacked-Cell-Block Design.
Thermal Performance of conventional cells verses Rolled-Ribbon
Cylindrical Cell
Pouch Cell
Prismatic Cell
Rolled-Ribbon Cell
Rolled-Ribbon cells are constructed by interleaving and winding long, narrow strips (ribbons) of anode, cathode, and separator materials onto a hub, producing an electrode roll (hence the term, “Rolled-Ribbon”). Winding electrodes is one of the oldest, lowest-cost, and most reliable methods for producing cells. The electrode roll is compressed between two pans that are separated by an insulated sealing ring, and the cell assembly is crimp-sealed. One pan serves as the cell’s anode terminal, and the other serves as its cathode terminal. The electrode ribbons in the electrode roll are perpendicular to the large, flat surfaces of the pans. The entire edge of the anode ribbon is in direct contact with the anode pan, and the entire edge of the cathode ribbon is in direct contact with the cathode pan. There are no welded tabs of any kind. These unique features are illustrated in the diagram below.
Cross-Section of Assembled Cell