New research from Apple details many ways to make batteries flexible enough to use with foldable screens in an iPhone or iPad, or to save space inside ordinary devices.
Flexible batteries mean screens that can fold or even be rolled up
The most obvious problem to solve for a foldable phone or tablet is the screen. We’ve also seen Apple working on hinged displays, as well as issues with the Samsung Galaxy Fold. However, there are other components that need to be flexible, and Apple is examining the batteries.
“Flexible battery structure”, US Patent No. 10,637,017, relates to how to power a foldable screen, but also seeks to resolve a recurring problem with all devices.
“Batteries often take up a lot of space in a portable electronic device,” he explains. “As the devices are consuming more and more energy, larger amounts of space must be dedicated to accommodate the space for the batteries.”
“In addition to taking up space, the batteries are also often quite rigid, which often makes placing the batteries in parts of a device designed to fold impractical,” he said. “When the battery is rigid and unable to withstand significant amounts of bending, the substantial part of the device that surrounds the battery is also unable to bend.”
Several of Apple’s proposals all focus on working with the two battery cells and the connections between them. “One solution … is to separate the flexible battery cells into discrete regions,” he says.
“For example, flexible battery cells can be wound in discrete cylinders and then spread over a flexible substrate,” he continues. “Depending on the interval between the discrete cylinders and the diameter of the discrete cylinders, the resulting battery can be flexible on at least one axis.”
A large part of the patent details various methods of mounting or stacking the battery cells, as well as details on the reduction of the stresses which this causes on the material of the battery. It could mean moving away from the familiar rectangular battery, and Apple also harnessed the idea of stackable batteries in the 2015 MacBook.
But, mainly, this patent concerns the “operation of a flexible battery integrated in [a] flexible display. “
“[The] flexible battery can be distributed on all four sides of [a] flexible signage, “he says.” For example, [the battery management unit] Both the BMU and the main logic board could be packaged in a case in which … is configured to retract by a retraction mechanism which drives a flexible display wrapped around a cylindrical member. “
It is the most direct reference in the patent to a rolled screen. Apple’s patent describes several ways to create flexible batteries, and everyone is concerned about the number of different types of display devices that can be created.
Detail of the patent illustrating an example of battery cells on a flexible support
The patent is awarded exclusively to Jiang Ai, who is also part of the team responsible for a previous patent for a foldable iPhone screen with a more robust radius of curvature.