Bipolar Nickel Metal Hydride Batteries for Aircraft Applications
Electro Energy Inc. has been developing their wafer cell bipolar nickel-metal hydride battery for aircraft applications. The design consists of individual sealed wafer cells that are stacked in series to make a multi-cell, multi voltage battery pack. Each individual wafer cell consists of one positive electrode, a separator material and a negative electrode contained in an outer envelope so that the faces of the wafer cell represent the positive and negative contact of the cell. The perimeter of the cell is sealed to contain battery gases and electrolyte, making a fully sealed cell. To construct a multi-cell battery, identical cells are stacked one on top of the other, such that, the positive face of one cell makes contact with the negative face of an adjacent cell to make a series connection. Multi-cell stacks are held in compression for physical integrity and to ensure good cell-to-cell contact.