Prismatic Cell
A prismatic cell is a battery cell sealed in a rigid, usually rectangular metal case. Its electrode assembly may be a flattened wound roll or a stack of individual or laminated layers. The format is defined by the enclosure, not by one mandatory internal assembly method. Pacific Northwest National Laboratory: Materials Review of Current/Near-Term Lithium Batteries
What the format changes
Flat sides allow close packing and provide broad surfaces that can interface with cooling plates and restraint structures. The rigid case supplies mechanical support and defined locations for terminals, seals, and pressure-control components. Its large flat walls and electrode assembly can still move as state of charge, temperature, and age change, so the pack must manage pressure and cooling contact.
Prismatic cells can use different electrode chemistries, and the shape alone does not establish usable energy, charging power, lifespan, or safety. Thermal and current gradients depend on cell dimensions, internal construction, and cooling as well as chemistry.
BYD's Blade Battery is a particular long, flat prismatic-cell implementation combined with an integrated pack design. Blade Battery is therefore not a synonym for every prismatic cell, and prismatic is not another term for Cell-to-Pack (CTP). BYD: Blade Battery technology overview
For detailed construction, cooling, support, and pack trade-offs, see Cell Formats.