14 DAY TRIAL // Apple has long strived to reduce the size of the batteries employed by its portable devices. According to a recent patent application filed with the U.S. Patent and Trademark office, Apple is taking its goal a step further.
According to the documentation available on the USPTO website, the invention would lead to significantly longer battery life in iPads, iPhones, MacBooks and other products that make use of lithium-ion or lithium-ion battery packs.
The Abstract of the invention notes that some embodiments provide “an improved rechargeable lithium battery.”
Apple explains that this rechargeable lithium battery includes a cathode current collector with a coating of cathode active material.
The battery also includes an electrolyte separator, and an anode current collector with a coating of anode active material.
“Within this rechargeable battery, the thickness of the coating of cathode active material and the thickness of the coating of anode active material are selected so that the battery will charge in a predetermined maximum charging time with a predetermined minimum cycle life when the battery is charged using a multi-step constant-current constant-voltage (CC-CV) charging technique,” Apple explains.
“Note that using the multi-step CC-CV charging technique instead of a conventional charging technique allows the thickness of the cathode active material and the thickness of the anode active material to be increased while maintaining the same predetermined maximum charging time and the same predetermined minimum cycle life,” the inventors outline.
“This increase in the thickness of the active materials effectively increases both the volumetric and gravimetric energy density of the battery cell.”
Simply put, using a multi-step, constant-current, constant-voltage (CC-CV) would increase the capacity of the battery without increasing its size.
According to a report by electronista covering the patent in question, present-day batteries need to use longer anodes and cathodes to draw in more current, thus making the battery bigger in size.