Apple patent application describes a simple way to boost battery life

For years now, we’ve been promised exciting new battery technologies that claim to dramatically boost battery life, and none of them ever seem to materialize. But a new Apple patent application describes a simple way to achieve a worthwhile increase in battery life with nothing more high-tech than a metal housing.

The invention is a little ironic, as it solves a problem Apple originally created back in 2015 with the batteries in the 12-inch MacBook, before subsequently adopting the same tech in the rest of the MacBook lineup …

In the 12-inch MacBook, Apple switched from rigid rectangular batteries to pouches that can be shaped to fit the available space. At the time, the company hailed that as a breakthrough tech, as it allowed batteries to fill all the free space inside the machine.

That offers a lot of flexibility, but the approach also creates problems, as Apple explains.

Lithium-polymer batteries are commonly used as rechargeable batteries to provide power to a variety of electronic devices, including laptop computers, tablet computers, mobile phones, personal digital assistants (PDAs), digital music players and cordless power tools. Lithium-polymer batteries can often include electrodes and electrolyte sealed in an aluminized laminated pouch. These pouch batteries can be used in space-constrained portable electronic devices such as mobile phones, laptop computer, and/or wearable devices.

The sealed edges of the pouch battery can result in excess pouch material and the pouch can have a positive voltage that requires the exterior surface of the pouch to be isolated from conductive surfaces in the electronic device. To accommodate the excess pouch material and isolate the conductive surface of the pouch battery, the pouch battery needs to be smaller than the area provided in the electronic device, resulting in wasted space. This is especially important in space-constrained portable electronic devices, where space is at a premium and the devices are commonly designed to accommodate the largest batteries possible.

To solve this, Apple proposes to stick to the irregular shapes that enable the batteries to make full use of the space, but swap a soft pouch for a rigid metal housing.

This disclosure describes various embodiments that relate to an improved battery for reducing space between the battery and electronic components in an electronic device. In some embodiments, a battery can include a rigid or semi-rigid housing contacting components in an electronic device.

For example, in some embodiments the battery includes an electrode and cathode surrounded by a metal housing. The battery can be sized to optimize the available space in the electronic device without the need for spacing between the battery housing and other components in the electronic device. In some embodiments, the metal housing can be connected to a common ground, to allow other components to contact the battery housing without causing a short circuit or corroding the components.

Additionally, the metal housing can be used as a structural element in the electronic device. For example, brackets can be attached to the metal housing or a flange between two housing pieces can be using as an attachment point. 

In that way, we’d get the best of both worlds.

In principle, that would allow increased battery capacity without increasing the thickness of the MacBook. This being Apple, however, one might suspect the company will take the opposite approach, and maintain the existing battery capacity while making the laptops thinner…