Flexible thin layer open electrochemical cell

Abstract

A flexible thin layer open liquid state electrochemical cell which can be used as a primary or rechargeable power supply for various miniaturized and portable electrically powered devices of compact design. The cell includes a wet electrolyte, yet maintains a fexible, thin and open configuration, thus devoid of accumulation of gases upon storage. The cell comprising a first layer of insoluble negative pole, a second layer of insoluble positive pole and a third layer of aqueous electrolyte, the third layer being disposed between the first and second layers and including a deliquescent material for keeping the open cell wet at all times; an electroactive soluble material for obtaining required ionic conductivity; and, a watersoluble polymer for obtaining a required viscosity for adhering the first and second layers to the third layer. The electrochemical cell of the present invention is preferably produced using a suitable printing technology.

Description

[0001]This is a continuation of application U.S. patent application Ser. No. 08 / 575,190, filed Dec. 20, 1995 now U.S. Pat. No. 5,652,043.FIELD AND BACKGROUND OF THE INVENTION[0002]The present invention relates to electrochemical cells which are used as battery power sources by converting chemical energy to electrical energy. More particularly, the present invention relates to a primary or rechargeable electrochemical cell to be used as a regular or rechargeable battery which accomplishes the conversion of chemical energy to electrical energy using a wet (e.g., liquid state) electrolyte, yet maintains a flexible thin layer and open configuration.[0003]The ever-growing development of miniaturized and portable electrically powered devices of compact design such as, for example, cellular phones, voice recording and playing devices, watches, motion and still cameras, liquid crystal displays, electronic calculators, IC cards, temperature sensors, hearing aids, pressure sensitive buzzers, ...

AI Technical Summary

Benefits of technology

[0008]According to the present invention there is provided a flexible thin layer open liquid state electrochemical cell which can be used as a primary or rechargeable power supply for various miniaturized and portable electrically powered devices of compact design. There is further provided a method of manufacturing such a cell. The flexible thin layer open electrochemical cell of the present invention includes a wet electrolyte, yet maintains a flexible, thin and open configuration, thus devoid of accumulation of gases upon storage.

[0025]According to still further features in the described preferred embodiments the cell further comprising at least one conductive layer improving the electronic conductivity of at least one of the first and second pole layers.

[0035]The present invention successfully addresses the short-comings of the presently known configurations by providing a flexible thin layer open electrochemical cell which does not accumulate gases upon storage, yet it is maintained wet and intact by the use of a deliquescent material for keeping it wet at all times and a watersoluble polymer for obtaining the required viscosity for adhering the pole layers to the aqueous electrolyte layer. Further qualities of the cell include having no outer rigid casting therefore it is thin light and flexible and may be manufactured in any size, shape, color and applied patterns, hence it is suitable for a variety of applications; cost effectiveness; made of environmental and human friendly materials; and, self sticking via an adhesive backing.

Problems solved by technology

Although solid state batteries have an inherent advantage, they do not dry out and do not leak, they suffer major disadvantages when compared with liquid state batteries since, due to limited diffusion rates of ions through a solid, their operation is temperature dependent to a much larger extent, and many operate well only under elevated temperatures.

Being closed cells, these batteries tend to swell upon storage due to evolution of gases which is a fatal problem in thin layer batteries having no mechanical support.

The pressure imposed by the accumulated gases leads to layer separation, thus turning the battery inoperative.

However, the polymer is limited in its effectiveness and the mercury is environmental hazardous.

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