“Where’s that battery gone? I can’t see it! And it still powers my phone…”
That could be the wonder of an older electronics hobbyist that, if transported into time a few years ahead, will open a mobile phone to see what’s powering it. Oki Printed Circuits Co Ltd has exhibited a technology that embeds a 170μm-thick thin-film all-solid-state lithium-ion (Li-ion) rechargeable battery into a regular printed circuit board (PCB).
Up to now, such systems had double layer capacitors embedded on themselves, but those capacitors had an issue: their leak current was pretty high. They could be used in mobile phones, for example, to store a certain amount of energy and use it when power consumption is at its peak. Quickly discharging capacitors needed repeated recharging cycles, which drained the battery quicker than normal.
The parameters of Oki’s new Li-Ion PCB-embedded battery are 4.2V and 0.7mAh. The exhibited sample was a 0.8mm-thick four-layer board embedded with the Li-Ion battery that turned on and off an LED lamp.
Oki hopes to commercialize their new invention in diverse products during 2011, by cooperating with corporate electronics manufacturers.
Embedding at small scale could, of course, be expanded to a larger scale if this kind of batteries are successful in real-world practice. Electric cars could also benefit from an embedded battery that is spread all over the vehicle in independent modules that could power various parts of the car. When they break, the embedded batteries would also be changed easily and cheaper than if a total replacement of a unique and bigger battery would be needed.
