JPS5819876A - Electrolyte - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrolytes for various types of electrochemical cells, "IIL flow generating cells or storage batteries. The electrolytes reduce electrode solubility, increase electrolyte conductivity, It also contains a complex agent that is added to the charge/discharge electrochemical reaction.

In the search for improved power sources, extensive research has been conducted to improve the performance, 4HC weight, and capacity of various electrochemical cells and storage batteries. The main applications for such devices are in the field of hearing aids, space hygiene equipment and electrically driven non-polluting vehicles. One concept of this research is to investigate the electrolytes used in such batteries. The factors of interest here are the conductivity of the current which causes capacitive corrosive effects on the electrodes and other battery components. These coefficients vary depending on the chain degree of the electrolyte, the temperature, and the solubility of the electrodes and additives. Another important consideration is the rate of charge transfer due to chemical reactions, and in the case of many rechargeable batteries, the formation of dendrites can degrade the electrode structure, reduce capacity and shorten the useful life. be.

Various additives were tested in different Makoto electrochemical cells,
Inorganic and organic additives, often used in the electroplating industry, are also being tested to suppress dendrite formation, increase charge transfer, reduce internal resistance, or overall improve battery performance and life. I was teased. Some references include the following:

US patent dated February 14, 1978! No. 4074028 (Wi11) An electrolyte to suppress dendrites and a rechargeable aqueous zinc-halogen battery filled with the electrolyte.

US Patent No. 3466195 dated September 9, 1969 (
Addition of silicate ions to the electrolyte.

U.S. Patent No. 3,433,679, dated March 18, 1969 (
Spellman F & B) lithium ions added to the electrolyte.

U.S. Patent No. 3,658,593, dated April 25, 1972 (
Caiola 8oc, A'cc, France,
) Tetrabutylammonium chloride of propylene carbonate 11g! +.

United States Patent Office No. 3540935 dated November 17, 1970 (Keating Nut EI Du Font)
Addition of sodium cyanide to prevent dendrites.

U.S. Patent No. 3,716,412, dated February 16, 1973 (
Peters B8P Ltd, U.) Acid Electrolyte vs. Amorphous Silica.

U.S. Patent No. 3,669,743, dated June 13, 1972 (
8windells Melpar) Zinc salt composite electrolyte.

Additives have also been added to the electrode structure to reduce capacity loss, electrode poisoning effects, or available materials have been effectively used to further enhance electrolyte penetration into the electrode structure.

Most modifiers and additives used so far are
They must be continuously recirculated in electrochemical cells because they can oxidize, reject, irreversibly react with, or dissipate electrodes and other battery components, rendering them ineffective. Adequate stability may not be obtained over long periods of time. The present invention addresses many of the problems mentioned above and uses an electrolyte in a manner that, depending on the cell wet electrode structure and configuration, improves the battery's efficient performance and economical aspects. be.

The chemical reactions during charging and discharging of various electrochemical cells are
It is not well understood and clarified, and many competing reactions are often involved. Those skilled in the art of electrochemical batteries will understand that the reactions are as applied to electroplating and rechargeable batteries and will therefore be familiar with the full details of the reactions that can be incorporated into the use of the present invention. Understanding is not superposition. Furthermore, the present invention is, of course, to be judged from the claims, but each reaction that occurs within a given electrochemical cell when using an electrolyte according to the present invention does not, in any case, constitute the scope of the present invention. It should not be considered limiting or limiting.

The electrolyte according to the invention can be used in high capacity pre-charged dry storage batteries, metal-air batteries, silver-zinc (Ag-Zn) batteries, nickel-cadmium (Ni-Cd) batteries, nickel-zinc (Ni-Zn) batteries. , nickel-iron (Ni-r
e) Useful for use in batteries, rechargeable batteries such as lead oxide (pbo) batteries, as well as metal-air batteries and other battery systems.

The components of the electrolyte and any initial additives of suitable shapes can be used equivalently in cells with different electrolytes, including the formation and activation of the various electrodes prior to incorporation into the cell.
The same applies to electroplating and electrochemical surface treatments. The original lj! Electrolytes based on ll1c generally improve conductivity and act as charge transfer media at low temperatures, reduce battery internal resistance by %, and increase battery potential by effectively utilizing the electrochemical capacity of the electrodes. , improve battery storage capacity and efficiency. In addition, in the case of rechargeable batteries, reduction of electrode solubility and change of electrode state j! can eliminate dendrite formation. In addition, in silver-zinc batteries, battery degradation due to silver transfer to the zinc electrode is greatly reduced, and the reusable life can be significantly extended without resorting to special sequestration.

The electrolyte can be potassium or sodium chloride or ferricyanide with or without cyanide or ferricyanide, which is the electrode material of the battery, as a solution electrolyte or in an electrochemical cell, a current generating cell or an accumulation Asahikawa. It is present as an additive in the electrolyte solution or salt form.

The metal (Fe) link retains the (CN) and avoids loss of the (Fe(cN)) complex that is actually added to the charge/discharge reaction during recirculation. Depending on the cell temperature electrode and electrolyte composition, the reduction of electrode solubility changes, which leads to shape change and loss of electrode capacity.

Reduces the effects of dendrite formation, etc. In particular in the case of rechargeable batteries with zinc electrodes, it is also advantageous to add additional small amounts of suitable fluorides, NaF or KF, and also to saturate the electrolyte with zincate. Beneficial.

The electrolyte according to the invention provides the following advantages when used in electrochemical cells as described above. Although these advantages are presented to a greater or lesser extent in all the concepts of the invention described below, they will not be described again individually in each embodiment.

1) Low battery internal resistance.

2) Good low temperature performance.

3) High output potential.

4) & good efficiency.

5) Use of good electrode materials.

6) Elimination of dendrite formation.

7) Long battery life.

The electrolyte according to the invention is prepared as follows.

That is, first prepare potassium hydroxide (KOH) with a concentration of 1.12 g/- in 20 r, and add 13 wt% potassium 7-erythyanide until a concentration of 1.14-1.2 Li is obtained (2.6 mol). (KBFe (CN)6)
is added. Also, 15g of (K) with 100mK of distilled water
OH) Granules 85% KOH and 4 g of potassium ferricyanide (KBFe(CN)s) are dissolved. This absolute ratio is not critical at all, and in most cases, the addition of very small amounts of potassium ferricyanide to the electrolyte in many cells is sufficient to improve performance.

The electrolyte concentrations used in various brood cells vary to a large extent and depend on the particular operating temperatures and conditions and the selection of electrolyte compositions or electrolyte additives used in accordance with the present invention for a given application in any given plant. The battery components and electrodes are chosen to match the reference standards, and trends in conditions may similarly vary and even fall outside the desired range set forth herein as reference. This in no way diminishes the value of the invention or the benefits claimed herein.

Examples: 1. According to one concept of the present invention, silver-zinc (Ag-Zn
) standard pre-charged dry cell batteries are charged with potassium ferricyanide (KB) until a concentration of 1.14'
Fe(CN)6) was added at 20C with a concentration of 1.
An electrolyte according to the invention is provided which consists of 12 Li potassium hydroxide (KOH). This battery produces high power and
It has low internal resistance and provides good efficiency and capacity.

2. According to another concept of the invention, nickel-cadmium A
(Ni-Cd) standard batteries are KOH or NaOH
Instead of the general electrolyte, an electrolyte made of the present gAK prepared in several of the above-mentioned wJ1 examples is supplied. This cell also provides improved characteristics and high power levels over conventional cells.

3. According to another concept of the present invention, nickel-iron (Ni-
The standard cells of Fe) fJi are likewise improved by the use of the electrolyte according to the invention.

4. According to another concept of the invention, cells of the metal-air type, preferably of zinc-air type, are likewise improved by the use of the electrolyte according to the invention.

5. According to another concept of the present invention, nickel-zinc (Nt
-Zn)! ill batteries are likewise improved by the use of the electrolyte according to the invention.

6. According to another concept of the present invention, a nickel-zinc (Ni-Zn) Ii rechargeable battery using an electrolyte according to the present invention has a very small amount of zincate ZnO added to the electrolyte. Common compound KV or NaF and! 'b2B40
7. has boron in the form of 3BO3 or orthobolic acid H2BO3.

In a preferred embodiment of the invention, the electrolyte according to the invention is used in a nickel-cadmium (Ni-Cd) rechargeable battery of conventional construction, the electrode structure being of pocket or sintered or Other beams may be provided with pervasive separators. As mentioned above, the electrolytic solution according to the present invention has
It is made on the principle of potassium hydroxide with a concentration of 1.12 g/- to which potassium ferricyanide (K3Fe (CN)s) is added so that the concentration increases to about 1.14-1.18 "/, /. The absolute ratio is Even if a very small amount of (K3Fe(CN)e) is added to the electrolyte, which is not critical at all,
It is enough to improve the priest performance.

In another preferred embodiment of the invention, the electrolyte is used in a conventional composition of nickel-zinc (Ni-Zn), which electrolyte has a concentration of 1.14 to 1.18 g, as in the embodiments described above.
It is made from a KOH solution with a concentration of 1.12 g/- to which potassium ferricyanide is added so that the concentration is 1.12 g/-. In the case of zinc-based electrodes in rechargeable batteries, small amounts of potassium fluoride KF or sodium fluoride A NaF and boron are added in the form of Na2B4O7, H3BO2 or ortho-oxalic acid H2BO3, etc. It has also been found that it is beneficial to saturate the electrolyte containing zincate ZnO so as to further suppress the solubility of the zinc electrode. Original BA
The K-based electrolyte is not limited to its use in the above embodiments, but can also be used in other electrode systems and additives.

Such additives are often used to alter electrode conductivity or overpotential, or to reduce gassing and self-discharge, to name a few examples, such as free carbon, Ni, Pb, etc.
Mn Mo V Ti Zr Hf Nb Hg etc. are al. When using electrolytes according to the present invention W14, it may be advantageous to add some such additives in the form of cyanides such as potassium cyanomercurate (KzHg(CN)4) or &1 ferricyanides. be.

Principles and preferred embodiments resulting from use of the invention.

Embodiment 1 Various advantages and improvements have been described in the above specification. However, inventions to be protected under and
These numbers are included merely for illustrative purposes rather than as a limitation. Those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit of the present invention.

Claims (1)

[Scope of Claims] 1. In an electrolyte for an electrochemical battery, a current generating battery, or a storage battery that uses an alkaline, neutral, weak acid, or organic electrolyte, the electrode material used in the battery is cyanide or An electrolytic solution comprising potassium or sodium ferro- or ferricyanide with or without ferricyanide. 2.Claim # that includes a compound! Electrolyte solution according to item 1. 3. The electrolytic solution according to claim S item 1 or 2m' to which 5112 salt or ortho #1 fluoric acid is added. The electrolytic solution according to any one of claims 1 to 3, which uses an electrolyte. 5. Claims for use in #l-zinc batteries or 采-cadmium batteries! The electrolyte solution according to any one of items 1 to 4. 6. The electrolytic solution according to any one of claims 1 to 4 for use in a nickel-cadmium battery. 7. An electrolytic solution according to any one of claims 1 to 4 for use in a nickel-iron battery. 8. The electrolytic solution according to any one of claims 1 to 4 for use in a nickel-zinc battery. 9. The electrolytic solution according to any one of claims 1 to 4 for use in metal-air cells, such as zinc-air cells, fuel cells, or solar cells. 10. The electrolyte cell or electrode system may contain oxides or compounds, such as transition element mercury oxide or mercury compound electrodes, used to change the electrode conductivity or overpotential etc. The electrolytic solution according to any one of items 9 to 9.