KR100210954B1 - Zincpowder for alkaline batteries - Google Patents

Abstract

The present invention relates to a zinc powder for alkaline batteries, comprising: (1) 1-95 ppm aluminum; 0.001-2 Bismuth, 0.005-2 Indium and 0.003-2 One of lead and; 0.003-2 Calcium, (2) 1-95 ppm Al, 0.001-2 Bismuth, 0.005-2 Indium and 0.003-2 Lead, (3) 1-95 ppm Al; 0.001-2 Bismuth and 0.005-2 One of indium; 0.003-2 Lead and; 0.003-2 Calcium, (4) 1-1000 ppm lithium and; 0.001-2 Bismuth and 0.005-2 Indium and 0.003-2 At least one of calcium, (5) 1-1000ppm lithium, 0.003-2 Lead, 0.003-2 Calcium, and 0.005-2 Indium, (6) 1-000 ppm lithium; 0.001-2 Bismuth; 0.003-2 Lead and; 0.005-2 Indium and 0.003-2 At least one of calcium, (7) 1-95 ppm aluminum; 1-1000 ppm lithium; 0.001-2 Bi, 0.005-2 Indium and 0.003-2 At least one of lead and; 0.003-2 Indium-containing powders with 50 ppm Al according to formulas (1) and (3) are excluded if they consist of calcium and the remaining zinc and unavoidable impurities are present in the metal and the metal comprises calcium.

Description

Zinc Powder for Alkaline Batteries

The present invention relates to zinc powder for alkaline batteries, and more particularly, to aluminum and / or lithium-containing zinc powder for alkaline batteries.

Aluminum-containing zinc powders are known from EP-A-0427315. Within this document, zinc base powder for alkaline batteries needs to be masked, which powder is 0.005-2. 0.0001-0.01 as well as aluminum At least one of elemental indium and REM, in addition to REM (REM includes rare earth metals or mixtures of rare earth metals) or zinc and unavoidable impurities, ; Bismuth 0.003-2 in addition to zinc and unavoidable impurities And at least one of elemental indium and REM is 0.0001-2 ; Lead 0.005-2 in addition to zinc and unavoidable impurities And at least one of elemental indium and REM is 0.0001-2 ; Lead 0.005-2 besides zinc and unavoidable impurities , Bismuth 0.003-2 And at least one of elemental indium and REM is 0.0001-2 It contains.

The first example in this document relates to a powder prepared by spraying a dissolution bath of the following composition; 220 ppm Al, 5 ppm La, 12 ppm Ce, 500 ppm Pb, 54 ppm In, the remainder being zinc purified by heat. The second example relates to a powder prepared by spraying a dissolution bath of the following composition: 600 ppm Al, 500 ppm Pb, 500 ppm Bi, 100 ppm In, the remainder being zinc purified by heat. All other specified examples are 0.03-0.06 To a powder with an aluminum content of being).

The powders according to this embodiment are common to each other in that they contain at least approximately 220 ppm Al and have excellent wear resistance in the electrolyte of the battery before or after partially discharging the battery. However, there are drawbacks, among other things, that can cause short circuits in certain types of batteries, LR6-type and smaller.

The object of the present invention relates to an aluminum and / or lithium-containing zinc powder for alkaline batteries, which is characterized by causing short circuiting to a much lesser extent than the powder according to the prior art EP-A-0427315 and having sufficient wear resistance. .

The powder according to the invention comprises (1) 1-95 ppm Al; 0.001-2 Bi, 0.005-2 In and 0.003-2 One of Pb and; 0.003-2 Ca,

(2) 1-95 ppm Al, 0.001-2 Bi, 0.005-2 In and 0.003-2 Pb,

(3) 1-95 ppm Al; 0.001-2 Bi and 0.005-2 In 0.003-2 One of Pb and; 0.003-2 Ca.

(4) 1-1000 ppm Li; 0.001-2 Bi and 0.005-2 One of In and; 0.003-2 Ca.

(5) 1-1000ppm Li, 0.003-2 Pb, 0.003-2 Pb, and 0.005-2 In,

(6) 1-1000 ppm Li; 0.001-2 Bi; 0.003-2 Pb and; 0.005-2 In and 0.003-2 One of Ca;

(7) 1-95 ppm Al; 1-1000 ppm Li; 0.001-2 Bi, 0.005-2 In and 0.003-2 One of Pb and; 0.003-2 Indium-containing powder with 50 ppm Al according to formulations (1) and (3) is excluded if it is composed of Ca, and the remaining zinc and unavoidable impurities are present in the metal and the powder does not contain calcium.

Indeed, with respect to aluminum in powders according to the present invention, the applicant has found that, in contrast to the powders according to the examples of EP-A-0427315, powders with low Al content do not or rarely cause short circuits in the batteries used. I knew that. Equally, the Applicant has found that, as demonstrated above, a very low Al content is sufficient to impart proper wear resistance to the powder after the battery has been partially or fully discharged. Other alloying elements (Bi and / or Pb and / or In) impart sufficient wear resistance to the powder before discharging. As a result, the powder is suitable for any form of alkaline batteries such as LR6, LR14, LR20 and the like. Likewise, Applicants have found that after partial or complete discharge, the effect of lithium on gas evolution is similar to that of aluminum. Both elements can, as a result, be used separately or together.

Here, the following points should be noted:

EP-A-0457354 is 0.01-1 based on the total quantity among many things In, 0.005-0.5 Pb and Bi one or two and 0.005-0.2 It relates to a zinc powder for alkaline batteries containing at least one of Li, Ca and Al. Various examples of powder compositions include Al free powder, Al ≧ 0.01 Powder with and also with 25 ppm of Al, but different from the powder of the invention in that it contains Ca, In and Bi and optionally Pb. However, it is described that lithium has the same effect as aluminum. None of the above documents suggests that a short circuit occurs under a higher Al content and that this problem can be solved without adding wear resistance to the powder by limiting the Al content to 1-95 ppm.

JP-A-62176053 is 0.001-0.5 In, 0.005-0.5 Pb, 0.005-0.5 Al, 0.005-0.5 One or more of Ti, Sn, Cd and Ga, 0.0001-0.5 At least one of Li, Na, K, Rb and Ce and 0.005-0.5 Amalgamated zinc powders containing at least one of Ni, Co and Te are described. As a result, the powders contain at least six alloying elements and are also amalgamated. From EP-A-0384975, lithium-containing zinc alloys are known which are used as cups for LeClanche batteries. Lithium is added to improve mechanical strength, i.e., features that are of no importance in the case of zinc powder for alkaline batteries.

It is an object of claims 2 to 41 to prepare a preferred powder composition according to the invention.

An easy way to prepare the powders of the present invention is to add all the additives (Al and for example In and Bi) which must be present in the powder to be produced, to spray the resulting alloy with a gas, water or a mixture of gas and water. It consists of letting.

Anyone can spray dissolved zinc containing some additives (such as Al and Bi), followed by bonding from an aqueous solution onto the powder sprayed with the remaining additives (such as In), or physical vapor deposition from the gas phase ( Physical gas deposition or PVD), or from the gas phase onto a powder sprayed by chemical vapor deposition (chemical gas deposition or CVD). If the additive is more positive than zinc, it is clear that the bonding technique can be applied. When more additives have to be attached to the sprayed powder, the additives can be attached simultaneously or separately attached.

Anyone can spray this dissolved zinc and then attach all additives on the sprayed powder.

It is possible to introduce certain additives in part by making zinc and the remaining material dissolved by deposition on the sprayed powder into an alloy.

Instead of spraying with gas, water or a mixture of gas and water, techniques such as centrifugal spraying or casting and polishing of cast metal suitable for converting the dissolved metal into powder may be applied.

If the desired powder comprises additives that can be bonded (such as In), then another method of preparing the powder is a powder with an additive that cannot be bonded and some that can be bonded according to one of the above-mentioned methods. It consists of preparing a powder with the additive of and producing a positive electrode from the resulting powder. The positive electrode is introduced into the battery and an additive which can be bonded is added to the electrolyte of the battery, and the additive can be bonded onto the powder of the positive electrode. The present invention consequently relates to powders as they are introduced into the battery as well as to the powder present in the battery.

This example demonstrates that the zinc base powder according to the present invention has excellent wear resistance in the electrolyte of the battery after partial discharge of the battery.

Seven powders with the following composition are prepared: Zn, 500 ppm Pb, 500 ppm Bi, 500 ppm In and 0, 5, 7, 16, 21, 70 and 280 ppm Al, respectively. For this purpose anyone starts with zinc that is thermally purified to add the alloying element in the desired amount in the dissolved state.

The resulting dissolution tank is homogenized at 450 ° C. by stirring. The molten alloy is produced to flow in a jet stream of compressed air, resulting in an alloy powder, the particles having the same uniform composition as the particles of the substantially uniform dissolution bath.

The alloy powder is sieved to separate at a fraction of at least 500 μm and possibly at most 104 μm, in which way an alloy powder with a particle size of 104 to 500 μm is obtained.

As alloy powder, anyone manufactures a battery of LR14-type. The battery is discharged at 2.2 mA for 2 hours. Thereafter, the amount of hydrogen which is spread at 45 ° C. for 7 days is measured. The results are summarized in the following table.

The results demonstrate that a small addition of Al significantly reduces the gas velocity.

Example 2

This example demonstrates that the zinc base powder according to the present invention has excellent wear resistance in the electrolyte of the battery after partial discharge of the battery.

Three powders with the following composition were prepared: Zn, 500 ppm In, 500 ppm Bi and 0.35 and 70 ppm Al, respectively. For this purpose, it can proceed in the same manner as in Example 1.

LR14-type batteries are made with alloy powder. The battery is discharged to 2.2 mA for 9 hours. Thereafter, the amount of hydrogen which is spread at 71 ° C. for 7 days is measured. Everyone gets results of 165, 101 and 73 μl / g.day, respectively.

Example 3

This example demonstrates that the zinc base powder according to the present invention does not cause a short circuit in the LR6-type battery.

Three powders with the following composition are prepared: Zn, 500 ppm In, 500 ppm Bi and 30, 70 and 325 ppm Al, respectively. For this purpose, it can proceed in the same manner as in Example 1.

The powder is provided to the battery manufacturer for use in LR6-type batteries. Battery manufacturers are not suitable for batteries of this type because powders with 325 ppm Al can cause short circuits, while powders with 30 and 70 ppm are suitable because the powders do not cause short circuits in batteries of the same type. Say.

Other general forms of embodiments according to the present invention have the following composition:

The powders contain only the specified additives, in addition to zinc and unavoidable impurities. Unavoidable impurities are those present in zinc and additives.

Claims (8)

Has a positive electrode, a negative electrode and an electrolyte, the positive electrode contains aluminum powder containing zinc powder as active material, zinc powder is 0.0016-0.0095wt Aluminum and 0.001-2wt Bismuth, 0.005-2wt 0.003-2wt with Indium Lead, and 0.003-2 Consists of one of calcium and the remaining zinc and inevitable impurities are present in the metal, zinc powder is only 0.01-0.5wt, in addition to zinc and inevitable impurities 0.005-0.2wt of bismuth and at least one of aluminum and calcium in total 0.005-0.5wt containing, and at the same time electrolyte based on zinc powder An alkaline battery comprising yttrium hydroxide prepared by reacting a yttrium salt as an initiator in a neutralization treatment in an aqueous solution in an amount of; And if the powder does not contain calcium, the zinc powder is 0.005 wt. An alkaline battery, wherein an alkaline battery containing aluminum is excluded. Has a positive electrode, a negative electrode and an electrolyte, the positive electrode contains aluminum powder containing zinc powder as active material, zinc powder is 0.0016-0.0095wt Aluminum and 0.001-2wt Bismuth, 0.005-2wt 0.003-2wt with Indium Lead, and 0.003-0.1 Consists of one of calcium and the remaining zinc and inevitable impurities are present in the metal, zinc powder is only 0.01-0.5wt, in addition to zinc and inevitable impurities Bismuth and 0.005wt in total of at least one of aluminum and calcium And at the same time 0.005-0.5wt electrolyte based on zinc powder An alkaline battery comprising yttrium hydroxide prepared by reacting a yttrium salt as an initiator in a neutralization treatment in an aqueous solution in an amount of; And if the powder does not contain calcium, the zinc powder is 0.005 wt. An alkaline battery, wherein an alkaline battery containing aluminum is excluded. Has a positive electrode, a negative electrode and an electrolyte, the positive electrode contains aluminum-containing zinc powder as active material, zinc powder is 0.0016-0.0045wt Aluminum and 0.001-2wt Bismuth, 0.005-2wt Indium, and 0.003-2wt Consisting of lead and remaining zinc and unavoidable impurities present in the metal, zinc powder is only 0.013wt, in addition to zinc and unavoidable impurities Bismuth, 0.05wt Indium and 0.003wt An alkaline battery, wherein an alkaline battery comprising aluminum is excluded. Has a positive electrode, a negative electrode and an electrolyte, the positive electrode contains aluminum-containing zinc powder as active material, zinc powder is 0.0016-0.0095wt Aluminum and 0.001-2wt Bismuth, 0.025-0.1wt Indium, and 0.003-2wt Consisting of lead and remaining zinc and unavoidable impurities present in the metal, zinc powder is only 0.013wt, in addition to zinc and unavoidable impurities Bismuth, 0.05wt Indium and 0.003wt Alkaline batteries comprising aluminum; And zinc powder is 0.005wt with indium An alkaline battery, wherein an alkaline battery comprising aluminum is excluded. An alkaline battery according to claim 1, wherein the powder contains a metal bonded from the electrolyte. The alkaline battery according to claim 2, wherein the powder contains a metal bonded from the electrolyte. The alkaline battery according to claim 3, wherein the powder contains a metal bonded from the electrolyte. The alkaline battery according to claim 4, wherein the powder contains a metal bonded from the electrolyte.