QuantumScape’s solid-state lithium-metal battery technology is designed to enable greater energy density, faster charging and enhanced safety compared to conventional lithium-ion batteries. However, the company says, lithium metal has some unique characteristics that require innovations in cell architecture—such as the uniaxial expansion of lithium metal as it plates and strips during charging and discharging.
To address these characteristics, QuantumScape has developed a new cell format it calls FlexFrame—a hybrid of conventional pouch and prismatic cell designs intended to enable a technological step-change improvement .
The FlexFrame architecture consists of a frame that wraps around the edge of the cell stack, and a flexible outer layer of polymer laminate similar to conventional pouch cell material.
When manufactured, the cell stack is in its most contracted position, with the face of the cell sitting around a millimeter below the frame. As the cell charges and the anodes of each layer are plated with pure lithium metal, the cell face is pushed out, along with the flexible packaging material. When fully charged, the face of the cell is designed to be almost totally flush with the frame.
In addition to accommodating expansion and contraction, FlexFrame is designed to allow the cell to simultaneously:
Dissipate excess heat during fast charging
Function with or without externally applied pressure
Enable high-volume manufacturing and pack integration
Offer good packaging efficiency to achieve cell-level energy density targets