JPS58206069A - Organic electrolyte battery - Google Patents

Abstract

PURPOSE:To reduce the variations in battery performances such as open-circuit voltage and internal resistance by using water glass as a binding agent for a positive mixture so as to cause the water glass to exhibit a moldability almost equal to that of polytetrafluoroethylene. CONSTITUTION:Water glass used as a binding agent in a positive mixture, is a concentrate aqueous solution of an alkali silicic-acid system glass. It has a molar composition of Na2O.nSiO2 (n ranges between 2.1 and 3.5), and contains 23-37% of SiO2, 6-18% of Na2O, less than 0.03-0.05% of Fe2O3 and less than 0.2% of insoluble matter. A positive mixture powder containing such water glass as a binding agent, is prepared by homogeneously mixing the water glass together with a positive active material such as manganese dioxide and a conductive auxiliary agent such as flake graphite in water, drying the mixture until its moisture content becomes around 18-17wt%, then granulating the mixture before the granulated mixture is formed into granular shapes, being followed by drying the granular mixture until is mixture content becomes around 0.5- 0.7wt% The thus prepared positive mixture powder is subjected to compression molding.

Description

【発明の詳細な説明】 この発明はリチウムを陰極活物質、二酸化マンガンを陽
極活物質とする有機電解質１に池の改良に係り、電池性
能のバラツキが少ない有機電解質電池を提供することを
目的とする。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvement of an organic electrolyte 1 using lithium as a cathode active material and manganese dioxide as an anode active material, and aims to provide an organic electrolyte battery with less variation in battery performance. do.

陰極活物質ｔしてリチウムを用い、電解質として各種の
有機溶剤に塩化物、過塩素酸塩、ホウフッ化塩などの電
解質を俗解させた有機液体を用いる有機電解質電池にお
いては、陽極活物質として保存中での溶解か少な（、か
つ単極電位の高い二酸化マンガンが多用されているが、
二酸化マンガンは付着水ならびに多波の結合水を有して
おり、それらが電池保存中にガスを発生して電池にふく
れを生じさせ、かつ電池性能を低下させるので、それら
の除去ならひに二酸化マンガンの相転移による放電特性
の平坦化をはかるために、二酸化マンガンを加熱処理す
る必要がある。In organic electrolyte batteries that use lithium as the cathode active material and organic liquids made from various organic solvents such as chloride, perchlorate, and fluoroborate salts as the electrolyte, it is stored as the anode active material. Although manganese dioxide is often used because it has a low solubility (and has a high unipolar potential),
Manganese dioxide has adhered water and multi-wave bound water, which generate gas during battery storage, cause swelling in the battery, and reduce battery performance. In order to flatten the discharge characteristics due to the phase transition of manganese, it is necessary to heat treat the manganese dioxide.

そのような二酸化マンガンの加熱処理に際して採用され
ている方法は、二酸化マンガンをりん状黒鉛などの導電
助剤や結着剤としてのポリテトラフルオルエチレンなど
と混合して加圧成形したのち約４００℃で加熱処理する
方法であるが、このような方法により加熱処理された陽
極合剤を用いた有機電解質電池では電池性能、と（に開
路電圧や円高抵抗などにバラツキか多発する。The method adopted for such heat treatment of manganese dioxide is to mix manganese dioxide with a conductive agent such as phosphorescent graphite and polytetrafluoroethylene as a binder, press-form it, and then heat-process the mixture to about 400 ml. Although this method involves heat treatment at ℃, organic electrolyte batteries using heat-treated anode mixtures often exhibit variations in battery performance, such as open-circuit voltage and high-yen resistance.

そのため、発明者らはそのようなバラツキが発生する原
因について種々検討を重ねたところ、陽極合剤の加熱処
理時にポリテトラフルオルエチレンや、あるいはポリテ
トラフルオルエチレンに付ｔｉする不純物が二酸化マン
ガンと反応して油状の生成物を生じ、この油状生成物が
電池内で電解液に溶出し、リチウム表面や陽極合剤表面
に達して開路電圧や内部抵抗などの電池性能に影響を与
えること、ならびに該油状生成物の生成状況は、同時に
多数の陽極合剤を加熱処理した場合、個々の陽極合剤間
でかなりバラツキがあり、その結果、前記のような事情
により電池性能にバラツキが発生することが判明した。Therefore, the inventors conducted various studies on the causes of such variations and found that during the heat treatment of the anode mixture, polytetrafluoroethylene or impurities attached to polytetrafluoroethylene may be caused by manganese dioxide. reacts with the metal to produce an oily product, and this oily product is eluted into the electrolyte within the battery and reaches the lithium surface and anode mixture surface, affecting battery performance such as open circuit voltage and internal resistance; In addition, when a large number of anode mixtures are heat-treated at the same time, the state of production of the oily product varies considerably among individual anode mixtures, and as a result, variations in battery performance occur due to the above-mentioned circumstances. It has been found.

そこで、この発明者らはポリテトラフルオルエチレンに
代わる結着剤を見出すべく鋭意研究を重ねた結果、水ガ
ラスを陽極合剤の結着剤として用いるときは、ポリテト
ラフルオルエチレンとほぼ同等の成形性が発揮され、か
つ開路電圧や内部抵抗などの電池性能のバラツキが少な
い有機電解質電池が得られることを見出し、この発明を
完成するにいたった。Therefore, the inventors conducted intensive research to find a binder to replace polytetrafluoroethylene, and found that when water glass is used as a binder for anode mixture, it is almost equivalent to polytetrafluoroethylene. It has been discovered that an organic electrolyte battery can be obtained that exhibits excellent moldability and has less variation in battery performance such as open circuit voltage and internal resistance, and has completed the present invention.

本発明の陽極合剤で使用する結着剤としての水ガラスと
は、アルカリ−ケイ酸系ガラスの濃厚水溶液をいい、モ
ル組成はＮｈＯ・ｎ５ｉＯ，（ｎ寓２．１〜３．５の軸
間である〕成分はＳｉｎ、２３〜３７、Ｎｕ□０６〜１
８　、　Ｆｅ、０．（０，０３〜０．０５゜不溶分＜０
．２％である。Water glass as a binder used in the anode mixture of the present invention refers to a concentrated aqueous solution of alkali-silicate glass, and has a molar composition of NhO. ] The components are Sin, 23-37, Nu□06-1
8, Fe, 0. (0.03~0.05゜Insoluble content<0
．． It is 2%.

このような水ガラスは、加圧成形後の陽極合剤の加熱処
理時においても、二酸化マンガンなどの陽極活物質と反
応せす、したがって放電容量の低下を生じることかなく
、マたポリテトラフルオルエチレンの場合のような油状
生成物を生じることがないので、開路ｌｋ比や門出抵抗
などの電池性能にバラツキが生じず、もとより貯蔵中に
おける電解液への油状生成物の溶出がないので貯蔵によ
る内部抵抗の増加も少ない。Such water glass reacts with the anode active material such as manganese dioxide even during the heat treatment of the anode mixture after pressure molding, and therefore does not cause a decrease in discharge capacity and can be used as a material for the anode mixture. Since it does not produce oily products as in the case of oleethylene, there is no variation in battery performance such as open circuit lk ratio and gate resistance, and there is no elution of oily products into the electrolyte during storage, so it can be stored easily. There is also little increase in internal resistance.

この発明において、水ガラスの使用量としては、少なす
ぎると結着剤としての作用が充分にはたせず、多すぎる
とそのぶん陽極活物質などの使用量が少な（なるので、
陽極活物質１００部（［１菫都、以十同様）に対して０
．２〜５．０部の軸間が好ましい。In this invention, if the amount of water glass used is too small, it will not function as a binder sufficiently, and if it is too large, the amount of anode active material etc. used will be reduced accordingly.
0 parts per 100 parts of anode active material ([1 Sumito, same as above)]
．． 2 to 5.0 parts interaxial is preferred.

そして、このような水ガラスを結着剤として用いた陽極
合剤粉末は、たとえはつきに示すようにして調製され、
加圧成形に供される。The anode mixture powder using such water glass as a binder is prepared as shown in the example,
Subjected to pressure molding.

すなわち、水ガラスを二酸化マンガンなどの陽極活物質
やりん状黒鉛などの導電助剤と水中で均一に混合し、水
分含１１１８〜１７％（Ｍ量％、以下間ｍ）程度に乾燥
したのち、造粒、整粒して顆粒状にし、ついで水分合波
が０．５〜０．７％程度になるｌで乾燥することによっ
て水ガラスを結着剤として用いた陽極合剤粉末が調製さ
れ、加圧成形に供される。That is, water glass is uniformly mixed in water with an anode active material such as manganese dioxide or a conductive agent such as phosphorous graphite, and after drying to a water content of about 1118 to 17% (M amount %, hereinafter referred to as m), An anode mixture powder using water glass as a binder is prepared by granulating and sizing to form granules, and then drying at a temperature where the combined water content is approximately 0.5 to 0.7%. Subjected to pressure molding.

この発明の有機電解質電池において使用する電解液とし
ては、有機電解質電池に通常便用される電解液かすべて
便通することができるか、たとえば炭酸プロピレン、ｌ
、２−ジメトキシエタン、テトラヒドロフラン、γ−ブ
チロラクトンなどの単独または２種以上の混合溶媒に過
塩素酸リチウムまたはホウフッ化リチウムを溶解させた
ものを使用するのか好ましい。The electrolyte used in the organic electrolyte battery of this invention may be any electrolyte commonly used in organic electrolyte batteries, such as propylene carbonate, l
It is preferable to use lithium perchlorate or lithium borofluoride dissolved in a solvent such as , 2-dimethoxyethane, tetrahydrofuran, or γ-butyrolactone alone or in a mixture of two or more thereof.

つぎに実施例をあげてこの発明を説明する。Next, the present invention will be explained by giving examples.

二酸化マンガン１００部、リン状黒鉛１０部およびケイ
酸ナトリウム２ｇからなる顆粒状陽極合剤２７０ｗｖを
１シーのプレス圧で予備成形し、これにステンレス鋼製
の金網を載置して６シーのプレス圧で加圧成形して直径
１６厘、厚み０５一の金網付き陽極合剤を作製し、これ
を４００℃で４時間加熱処理したのち、室ａまで冷却し
た。A granular anode mixture of 270 wv consisting of 100 parts of manganese dioxide, 10 parts of phosphorous graphite, and 2 g of sodium silicate was preformed at a press pressure of 1 sea, and a stainless steel wire mesh was placed on it and pressed for 6 seas. An anode mixture with a wire gauze having a diameter of 16 mm and a thickness of 0.5 mm was prepared by pressure molding, which was heat-treated at 400° C. for 4 hours, and then cooled to room a.

この陽極合剤を用い、つぎに示すように電池組立を行い
、第１図に示す有機電解質電池を製造した。Using this anode mixture, a battery was assembled as shown below, and the organic electrolyte battery shown in FIG. 1 was manufactured.

すなわち、陰極缶（１）の内命にスポット溶接されたス
テンレス鋼製の網（２）に直径１４厘、厚さ０２５諺の
リチウム円板を圧着して陰極剤（３）となし９いでポリ
プロピレン不織布よりなるセパレータ（４）を載置し、
電解液の大半を注入したのち、その上に前記陽極合剤（
５）をそのステンレス鋼網（６）側を上にして載置し、
残りの電解液を滴−トしたのち、その上から陽極缶（７
）をかぶせ陽極缶（７）の開口部を内方へ締め付けてそ
の内面を陰極缶（１１の周辺部に嵌着させたポリプロピ
レン製の環状ガスケット（８）に圧接して封口し、上下
を反転させて第１図に示す有機電解質電池を製造した。That is, a lithium disk with a diameter of 14 mm and a thickness of 0.2 mm was crimped onto a stainless steel mesh (2) spot-welded to the interior of the cathode can (1), and a polypropylene plate was prepared with a polypropylene material (9) to form the cathode agent (3). Place a separator (4) made of non-woven fabric,
After injecting most of the electrolyte, the anode mixture (
5) with its stainless steel mesh (6) side facing up,
After dropping the remaining electrolyte, place an anode can (7
), tighten the opening of the anode can (7) inward, press the inner surface of the anode can (7) against the annular polypropylene gasket (8) fitted around the periphery of the cathode can (11), and seal it, then turn it upside down. In this way, an organic electrolyte battery shown in FIG. 1 was manufactured.

なお、この電池の電解液としては、炭酸プロビレント１
．２−ジメトキシエタンとの容量比カ３５：６５の混合
溶媒に過塩素酸リチウムを０．５モル／ｊの割合で溶解
させたものが使用された。The electrolyte for this battery is Provirent Carbonate 1.
．． A solution prepared by dissolving lithium perchlorate at a ratio of 0.5 mol/j in a mixed solvent with 2-dimethoxyethane at a volume ratio of 35:65 was used.

このようにして製造された電池Ａについて製造より２０
℃で１日後、２０℃で７日後および２０℃で３５日間貯
蔵後の内部抵抗を測定した結果を後記第１表に示す。な
お試験に供された電池は５０個で、第１表にはそれらの
電池について測定した内部抵抗の平均値および標準偏差
が示されている。なお内部抵抗の測定は１１ｕ−ｉｚの
交流法で行なった。Regarding battery A manufactured in this way, 20
The internal resistance was measured after 1 day at 20°C, 7 days at 20°C, and 35 days at 20°C, and the results are shown in Table 1 below. Note that 50 batteries were tested, and Table 1 shows the average value and standard deviation of the internal resistance measured for these batteries. Note that the internal resistance was measured by an 11u-iz alternating current method.

比較例１ 水ガラスに代えてポリテトラフルオルエチレンを用いた
ほかは実施例１と同様にして有機電解質電池を製造した
。Comparative Example 1 An organic electrolyte battery was produced in the same manner as in Example 1 except that polytetrafluoroethylene was used instead of water glass.

このようにして製造された電池Ｂについて実施例１と同
様の条件下で内乱抵抗を測定した結果を第１表に示す。Table 1 shows the results of measuring the internal disturbance resistance of Battery B thus manufactured under the same conditions as in Example 1.

第　　１　　表 ｊ８１表に示されるように、この発明の電池Ａは結着剤
としてポリテトラフルオルエチレンを用いた電池Ｂに比
べて内部抵抗の平均値および標準偏差か小さい。As shown in Table 1, Table j81, the average value and standard deviation of the internal resistance of the battery A of the present invention are smaller than that of the battery B using polytetrafluoroethylene as a binder.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの発明の４４！！Ａ電解質電池の一実施例を
示す断面図である。 （３）・・・陰極剤、（５）・・・陽極合剤出願人　　
日立マクセル株式会社 代表者　　永　　井　　　　　厚 第１図Figure 1 shows 44! of this invention! ! It is a sectional view showing one example of A electrolyte battery. (3)...Cathode agent, (5)...Anode mixture Applicant
Hitachi Maxell Ltd. Representative Atsushi Nagai Figure 1

Claims (1)

【特許請求の範囲】[Claims] １、　リチウムを陰極活物質、二酸化マンガンを陽極活
物質とする有機電解質電池において、陽極合剤の結着剤
として水ガラスを用いたことを特徴とする有機電解質電
池。1. An organic electrolyte battery comprising lithium as a cathode active material and manganese dioxide as an anode active material, characterized in that water glass is used as a binder for the anode mixture.