If smartphones revealed “problem batteries”, the growing popularity of wearable gadgets, this problem was exacerbated.
Alas, the battery capacity is not enough for a truly comfortable use of mobile and wearable devices. Electronics developers and manufacturers understand the depth of the problem, but batteries improve very slowly. Time after time, we hear the request to wait a few more years. That’s Sony, which last week at the 56th Symposium “Battery” showed an interesting prototype of the battery, also offers to wait a few years and then… then it will start producing capacious, reliable, flexible and “endless” solid-state batteries.
Solid-state electrolyte has become another fetish for developers. It is not flammable in case of short interlayer circuit as a conventional liquid or pasty electrolytes. It allows you to store more energy in the charging layer. It is easier to manufacture and has a number of other advantages. To all this, the prototype battery Sony solid-state electrolyte uses as an anode amorphous material, and not in crystalline form, as usual. This opens the way to the production of batteries at room temperature, since the production of electrodes with a crystal structure requires high-temperature processing. Also, the new Sony battery promises to be flexible and not collapsing from bending.
For the production of batteries with solid electrolyte, the company uses printing technology with sputtering. Layers of anode, solid electrolyte and cathode are consistently applied to a flexible polycarbonate base with a thickness of 400 µm. The solid electrolyte is oxynitride of lithium phosphate (LiPON). This material belongs to the group of lithium-ion conductors. The thickness of the electrolyte is 500 nm. Nickel, manganese, cobalt, copper or silver are used as a transition metal for the anode. Nickel showed the best ratio, providing a prototype capacity of 330 mA*h/g. In addition, the prototype battery remained operational after 2000 discharge/charge cycles, which is more than twice the life of mass batteries.
Sony is confident that in the next few years they will be able to bring the development to mind. The main problem that remains to be solved is the rapid self-discharge of the battery with a solid electrolyte. All the forces of the company’s engineers will be directed to this goal.