JP2005302426A - Manufacturing method of battery positive and negative electrode mixture and non-aqueous electrolytic solution battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize discharge performance of a battery by reducing fluctuation of mass of a positive and a negative electrode mixture. <P>SOLUTION: This is a manufacturing method of a positive and a negative electrode mixture in which positive and negative electrode acting materials are respectively mixed with a conductive agent and a binder, and these are granulated by extrusion method, and after a drying process and a classification process are applied, a forming process is applied. Among them, the drying process is carried out by a fluidized drying method. For example, the granulation mixture 17 extruded from an extrusion granulating machine 11 is dropped into a fluidized drier 12 by natural falling and dried by warm and hot air by flowing. Thereby, the strength of the pellet molded is improved and fluctuation of mass is eliminated. The battery using the positive and the negative electrodes manufactured by this method is stabilized in discharge performance. In particular, this is suitable for a non-aqueous electrolytic solution battery. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

Translated fromJapanese

本発明は、電池の正極合剤および負極合剤の製造方法およびこれらの正負極合剤より得られた電極を使用した非水電解液電池に関する。  The present invention relates to a method for producing a positive electrode mixture and a negative electrode mixture of a battery, and a non-aqueous electrolyte battery using an electrode obtained from these positive and negative electrode mixtures.

非水電解液電池は、従来主として電子手帳、電子計算機、携帯電話機等のコードレス機器用メモリーバックアップ等の電源として用いられてきたが、近年これらの機器の主電源としても用いられるようになってきた。主電源として用いる場合、使用する電池数は２個または３個で、これらを並列および直列で使用することが多く、安全性を高める上で電池容量の安定化が要求されてきている。  Non-aqueous electrolyte batteries have been used mainly as power sources for memory backup for cordless devices such as electronic notebooks, electronic computers, and mobile phones, but have recently been used as main power sources for these devices. . When used as a main power source, the number of batteries to be used is two or three, and these are often used in parallel and in series, and stabilization of the battery capacity has been required to improve safety.

図３は、代表的な非水電解液電池であるコイン形リチウム電池の概略断面図である。この図において、負極封口板１内には、リチウムまたはリチウム合金等で構成された負極２が収納されており、正極容器６には正極体４が収納されている。正極体４は、二酸化マンガン、フッ化黒鉛等の正極作用物質を導電剤や結着剤とともに混合し、ペレット状に成形させたものである。負極２と正極体４とはセパレータ３を介して対向配置されており、封口パッキング５が負極封口板１と正極容器６との間に介在して両者を絶縁している。さらにカシメ工程により正極容器６の上縁部をカールさせて電池を封口している。  FIG. 3 is a schematic cross-sectional view of a coin-type lithium battery which is a typical non-aqueous electrolyte battery. In this figure, anegative electrode 2 made of lithium or a lithium alloy is accommodated in a negative electrode sealing plate 1, and a positive electrode body 4 is accommodated in apositive electrode container 6. The positive electrode body 4 is obtained by mixing a positive electrode active material such as manganese dioxide and fluorinated graphite together with a conductive agent and a binder, and molding the mixture into a pellet shape. Thenegative electrode 2 and the positive electrode body 4 are disposed to face each other with the separator 3 interposed therebetween, and a sealingpacking 5 is interposed between the negative electrode sealing plate 1 and thepositive electrode container 6 to insulate them. Further, the upper edge portion of thepositive electrode container 6 is curled by a caulking process to seal the battery.

このような非水電解液電池において、一般的に正極は、図４に示すような方法で製造されている。すなわち、正極作用物質（二酸化マンガン）を導電剤（人造黒鉛）や結着剤とともに混合・攪拌し、膨潤剤を加えてさらに攪拌し、これを押出し方式で造粒したもの（例えば、特許文献１参照）、あるいは押出し造粒したものを円板上に投入して球形に成形したもの（例えば、特許文献２参照）、を容器に載せて高温雰囲気で乾燥させ、次に篩で分級して顆粒状とする。この顆粒状の正極をペレット状に成形して正極体を得る。  In such a non-aqueous electrolyte battery, the positive electrode is generally manufactured by a method as shown in FIG. That is, a positive electrode active substance (manganese dioxide) is mixed and stirred together with a conductive agent (artificial graphite) and a binder, added with a swelling agent, further stirred, and granulated by an extrusion method (for example, Patent Document 1). (Refer to Patent Document 2), which has been extruded and granulated into a disk and placed into a spherical shape (for example, see Patent Document 2), dried in a high-temperature atmosphere, and then classified with a sieve. The shape. The granular positive electrode is formed into a pellet to obtain a positive electrode body.

上記コイン形リチウム電池では、負極はリチウムまたはリチウム合金等で構成されているが、非水電解液二次電池では、負極は、例えば、リチウムイオンを吸蔵放出する炭素質材料と結着剤、導電材とを混練した負極合剤より作製したものも使用されており、その場合には上記正極体とほぼ同じようにして負極体を得ている。  In the coin-type lithium battery, the negative electrode is made of lithium or a lithium alloy. In the non-aqueous electrolyte secondary battery, the negative electrode is, for example, a carbonaceous material that absorbs and releases lithium ions, a binder, and a conductive material. What was produced from the negative electrode mixture which knead | mixed the material is also used, and the negative electrode body is obtained like the said positive electrode body in that case.

ところが、上記の製造方法によると、造粒したものを容器（例えば、金属製バットまたは金網）に載せて高温雰囲気で乾燥させたときに、処理量が多いとその重さによって造粒したものが押しつぶされ、カサ密度や顆粒合剤の粒径にバラツキが生ずることがある。このバラツキにより、ペレット状に成形したときに、得られた正極合剤の質量が安定せず、その結果電池の放電性能に影響を及ぼすことになる。  However, according to the above manufacturing method, when the granulated product is placed on a container (for example, a metal vat or a metal mesh) and dried in a high temperature atmosphere, if the amount of treatment is large, the granulated product is weighted. Crushing may cause variations in the bulk density and particle size of the granule mixture. Due to this variation, when formed into a pellet, the mass of the obtained positive electrode mixture is not stabilized, and as a result, the discharge performance of the battery is affected.

また、負極合剤の場合も同様に、炭素質材などの負極物質を導電剤や結着剤と混合・攪拌して、押出し方式で造粒する場合に、乾燥工程で上記の問題が発生する。
特開平１０−５５８０１号公報特開平９−１８０７０９号公報Similarly, in the case of a negative electrode mixture, when the negative electrode material such as a carbonaceous material is mixed and stirred with a conductive agent or a binder and granulated by an extrusion method, the above problem occurs in the drying process. .
JP-A-10-55801 JP-A-9-180709

本発明はこのような問題に対処してなされたもので、本発明の解決しようとする問題点は、電池の正極合剤および負極合剤の製造方法を改良してこれら合剤のカサ密度や顆粒合剤の粒径のバラツキをなくし、それによって電池特に非水電解液電池の放電性能を安定化させることである。  The present invention has been made in response to such problems, and the problem to be solved by the present invention is that the manufacturing method of the positive electrode mixture and the negative electrode mixture of the battery has been improved to improve the bulk density of these mixtures. It is to eliminate the variation in the particle size of the granule mixture, thereby stabilizing the discharge performance of the battery, particularly the non-aqueous electrolyte battery.

すなわち本発明は、正極作用物質または負極作用物質を導電剤および結着剤と混合し、これを押出し方式で造粒し、さらに乾燥、分級した後成形する電池正極合剤または負極合剤の製造方法において、上記乾燥工程を流動乾燥方式で行うことを特徴とする。
また、本発明は、上記の製造方法で製造した正極合剤または負極合剤を正極または負極として用いたことを特徴とする非水電解液電池に関する。That is, the present invention relates to the production of a battery positive electrode mixture or negative electrode mixture in which a positive electrode active material or a negative electrode active material is mixed with a conductive agent and a binder, granulated by an extrusion method, dried, classified, and then molded. In the method, the drying step is performed by a fluidized drying method.
The present invention also relates to a non-aqueous electrolyte battery characterized in that the positive electrode mixture or the negative electrode mixture manufactured by the above manufacturing method is used as a positive electrode or a negative electrode.

本発明における流動乾燥方式で行う乾燥工程を具体的に示すと、例えば、押出し造粒機から押出された造粒合剤を温風または熱風が吹き上げている流動乾燥機中に自然落下させ、造粒合剤が温風または熱風で煽られるようにして流動しながら乾燥させる方法である。  Specifically, the drying process performed by the fluidized drying method in the present invention is, for example, the granulation mixture extruded from the extrusion granulator is naturally dropped into a fluidized dryer where hot air or hot air is blown up, In this method, the granule is dried while flowing so as to be beaten with hot air or hot air.

本発明では上記したように造粒した後の乾燥を流動方式で行うので、造粒したものが押しつぶされることがなく、そのためカサ密度を従来より低下させることができ、成形性がよくなってペレット状に成形された正極体・負極体の強度が向上する。また、顆粒合剤の粒径が安定するので、ペレット成形時の質量のバラツキが低減し、電池の放電性能が安定する。この製造方法は特に非水電解液電池の電極合剤の場合に適しており、かかる製造方法で得られた正極合剤，負極合剤を用いた非水電解液電池は放電性能が極めて安定したものとなる。  In the present invention, as described above, drying after granulation is performed in a fluidized manner, so that the granulated material is not crushed, so that the bulk density can be lowered as compared with conventional pellets, and the moldability is improved and the pellets are improved. The strength of the positive electrode body / negative electrode body formed into a shape is improved. In addition, since the particle size of the granule mixture is stabilized, variation in mass at the time of pellet molding is reduced, and the discharge performance of the battery is stabilized. This manufacturing method is particularly suitable for the electrode mixture of a non-aqueous electrolyte battery, and the non-aqueous electrolyte battery using the positive electrode mixture and the negative electrode mixture obtained by such a manufacturing method has extremely stable discharge performance. It will be a thing.

図１に本発明の正極合剤の製造方法をその工程図で示す。図１に示すように、二酸化マンガン（正極作用物質）、人造黒鉛（導電剤）および結着剤（結着剤）を混合攪拌し、次に膨潤剤を加えて攪拌し、これらを押出し造粒機に入れて押出し、造粒する。押出された造粒合剤をそのまま流動乾燥機に落下させて、乾燥させる。流動乾燥機内には熱風が旋風となって吹き込んでいるので、造粒合剤はこの熱風に煽られて流動しながら乾燥される。このようにして乾燥した造粒合剤を篩にかけて粒径を揃え、ペレット状に成形し、乾燥して正極を得る。  FIG. 1 is a process diagram showing a method for producing a positive electrode mixture of the present invention. As shown in FIG. 1, manganese dioxide (positive electrode active substance), artificial graphite (conductive agent) and binder (binder) are mixed and stirred, then a swelling agent is added and stirred, and these are extruded and granulated. Extrude into a machine and granulate. The extruded granulated mixture is dropped as it is on a fluid dryer and dried. Since the hot air is blown into the fluid dryer as the whirl, the granulated mixture is blown by the hot air and dried while flowing. The granulated mixture thus dried is sieved to make the particle size uniform, formed into pellets, and dried to obtain a positive electrode.

（実施例１）
まず、正極作用物質として二酸化マンガン５０ｋｇを用い、これに導電剤として人造黒鉛１０ｋｇ、結着剤としてポリテトラフルオルエチレンを加えて混合・攪拌し、さらに膨潤剤としてポリアクリル酸を水酸化リチウム水溶液に溶解させたものを添加し、攪拌を行い湿潤合剤とした。この湿潤合剤を目開きが直径０．４ｍｍのスクリーンを備えた押出し造粒機にて、押出し造粒を行った。このとき、押出される造粒合剤を流動乾燥機（不二パウダル株式会社製 ミゼットドライアー ＭＤ−Ｂ４００型）に自然落下させ、乾燥機炉温度１２０℃にて流動乾燥を行った。この流動乾燥の様子を図２に示す。(Example 1)
First, 50 kg of manganese dioxide is used as the positive electrode active substance, 10 kg of artificial graphite is added as a conductive agent, polytetrafluoroethylene is added as a binder, and the mixture is stirred. What was dissolved in was added and stirred to obtain a wet mixture. This wet mixture was subjected to extrusion granulation in an extrusion granulator equipped with a screen having an aperture of 0.4 mm. At this time, the granulated mixture to be extruded was naturally dropped onto a fluid dryer (Midget Dryer MD-B400, manufactured by Fuji Paudal Co., Ltd.), and fluidized and dried at a dryer furnace temperature of 120 ° C. This fluid drying is shown in FIG.

図２に示されるように、流動乾燥機１２は被乾燥物挿入塔１３、ファン室１４、温風通路１５およびヒーター１６からなっていて、ヒーター１６で熱せられた温風または熱風は温風通路１５を通ってファン室１４に達し、そこから被乾燥物挿入塔１３へ旋風となって吹き上げられる。一方、押出し造粒機１１のスクリーン１１ａから押出された造粒合剤１７は、流動乾燥機１２の被乾燥物挿入塔１３の中へ落下して、旋風となった温風または熱風によって煽られ、流動しながら乾燥される。  As shown in FIG. 2, thefluid dryer 12 includes anobject insertion tower 13, afan chamber 14, ahot air passage 15, and aheater 16, and the hot air or hot air heated by theheater 16 is a hot air passage. 15, reaches thefan chamber 14, and from there is blown up into the dryingobject insertion tower 13 as a whirlwind. On the other hand, the granulation mixture 17 extruded from thescreen 11a of the extrusion granulator 11 falls into the dryingobject insertion tower 13 of the fluidizeddryer 12, and is beaten by hot air or hot air that has turned into a whirl. Dried while flowing.

このようにして乾燥した造粒合剤１０ｋｇを篩にかけて顆粒合剤とし、粒度の確認を行った。また、容積５００ｍＬの容器にこの顆粒合剤を収納し、嵩密度の測定を行った。
上記により篩い分けした７１０μｍ〜１８０μｍの顆粒合剤を、質量０．４５ｇ、厚さ０．８ｍｍ、外径１６ｍｍのペレット状に成形し、これを２５０℃で乾燥して正極体４を作製した。この正極体４を図３に示すコイン形リチウム電池の正極体として用いて、正極容器６内へ収納した。The granulated mixture 10 kg dried in this way was sieved to obtain a granular mixture, and the particle size was confirmed. Moreover, this granule mixture was accommodated in the container of capacity 500mL, and the bulk density was measured.
The granule mixture of 710 μm to 180 μm sieved as described above was formed into a pellet shape having a mass of 0.45 g, a thickness of 0.8 mm, and an outer diameter of 16 mm, and dried at 250 ° C. to prepare the positive electrode body 4. Using this positive electrode body 4 as a positive electrode body of the coin-type lithium battery shown in FIG.

電解液として、プロピレンカーボネートと１，２−ジメトキシエタンの混合溶媒に過塩素酸リチウムを溶解させたものを用い、これを厚さ０．１５ｍｍのセパレータ３に含浸させ、負極２と正極体４との間に介在させた。また、負極封口板１、正極容器６との間に封口パッキング５を介在させてカシメ加工により封口し、正極容器６の上縁をカールさせて、電池総高１．６ｍｍ、外径２０ｍｍの電池（型名：ＣＲ２０１６）を作製した。  As an electrolytic solution, a solution obtained by dissolving lithium perchlorate in a mixed solvent of propylene carbonate and 1,2-dimethoxyethane was impregnated in a separator 3 having a thickness of 0.15 mm, and thenegative electrode 2 and the positive electrode body 4 Between. In addition, a sealingpacking 5 is interposed between the negative electrode sealing plate 1 and thepositive electrode container 6 and sealed by caulking, and the upper edge of thepositive electrode container 6 is curled to obtain a battery having a total battery height of 1.6 mm and an outer diameter of 20 mm. (Model name: CR2016) was produced.

（比較例１）
従来の方法により正極合剤を製造した。図４にその製造方法を図式化して示す。
押出し造粒までの工程を実施例１と全く同様に行った。この押出し後の造粒合剤５０ｋｇを、６０ｃｍ×４０ｃｍのステンレス製金網に各１０ｋｇずつに分けて載置し、これを炉温度１２０℃の乾燥炉へ入れて保管し、水分を蒸発させた。(Comparative Example 1)
A positive electrode mixture was produced by a conventional method. FIG. 4 schematically shows the manufacturing method.
The steps up to extrusion granulation were carried out in the same manner as in Example 1. 50 kg of the granulated mixture after extrusion was placed on a 60 cm × 40 cm stainless steel wire mesh in 10 kg portions, which was placed in a drying furnace at a furnace temperature of 120 ° C. and stored to evaporate moisture.

乾燥後の造粒合剤１０ｋｇを篩にかけて顆粒合剤とし、実施例１と同様に粒度の確認を行った。また、容積５００ｍＬの容器にこの顆粒合剤を収納し、嵩密度の測定を行った。
上記の顆粒合剤を用い、実施例１と同様の方法により図３に示す電池を作製した。
上記実施例１および比較例１において測定した粒度分布状態および嵩密度の結果を以下の表１に示す。

10 kg of the granulated mixture after drying was sieved to obtain a granular mixture, and the particle size was confirmed in the same manner as in Example 1. Moreover, this granule mixture was accommodated in the container of capacity 500mL, and the bulk density was measured.
A battery shown in FIG. 3 was produced in the same manner as in Example 1 using the above granule mixture.
The results of the particle size distribution state and bulk density measured in Example 1 and Comparative Example 1 are shown in Table 1 below.

表１に示されるように、実施例１で作製した正極顆粒合剤は、粒径が３５５μｍを中心に揃っており、バラツキが少ない。これに対して比較例１で得られた正極顆粒合剤は広範囲の粒径分布となっていることがわかる。また、嵩密度も実施例１の場合は低下していることがわかる。  As shown in Table 1, the positive electrode granule mixture produced in Example 1 has a uniform particle size centered at 355 μm and has little variation. In contrast, it can be seen that the positive electrode granule mixture obtained in Comparative Example 1 has a wide particle size distribution. Moreover, it turns out that the bulk density is also reduced in the case of Example 1.

次に、実施例１および比較例１で作製した電池１００個を用い、放電抵抗１５ｋΩで連続放電を実施した。その放電容量を表２に示す。

Next, 100 batteries produced in Example 1 and Comparative Example 1 were used, and continuous discharge was performed with a discharge resistance of 15 kΩ. The discharge capacity is shown in Table 2.

上記表２に示すように、実施例１の電池では放電性能が比較例１の電池に比べて安定していることがわかる。これは、顆粒合剤の粒径が揃って安定したことにより、顆粒合剤をペレット状に成形する際、質量のバラツキが減少したことによるものである。As shown in Table 2 above, it can be seen that the discharge performance of the battery of Example 1 is more stable than that of the battery of Comparative Example 1. This is because the variation in mass was reduced when the granule mixture was formed into pellets due to the uniform particle size of the granule mixture.

また、実施例１および比較例１で作製したペレット状の正極合剤を２０個用いてその強度を測定した。その結果を表３に示す。なお、測定方法は、外径１６ｍｍ、内径１４ｍｍの円柱にペレット状正極合剤を載せ、直径５ｍｍの加圧棒で上部より押し、ペレット状正極合剤が破壊するまでの強度を測定する方法である。

Moreover, the strength was measured using 20 pellet-shaped positive electrode mixtures produced in Example 1 and Comparative Example 1. The results are shown in Table 3. The measuring method is a method in which a pellet-shaped positive electrode mixture is placed on a cylinder having an outer diameter of 16 mm and an inner diameter of 14 mm, and is pressed from above with a pressure bar having a diameter of 5 mm to measure the strength until the pellet-shaped positive electrode mixture breaks. is there.

上記表に示されるように、実施例１のペレット状正極合剤では強度が向上し、バラツキも減少していることがわかる。これは、流動乾燥方式を用いたことにより合剤の嵩密度が低下し、それによって成形後における合剤強度が向上した結果である。  As shown in the above table, it can be seen that the pellet-like positive electrode mixture of Example 1 has improved strength and reduced variation. This is a result of the decrease in bulk density of the mixture due to the use of the fluidized drying method, thereby improving the strength of the mixture after molding.

（実施例２）
まず、ノボラック樹脂を窒素雰囲気中で９５０℃で焼成した後、さらに２０００℃で加熱することによりこれを炭素化し、それを平均粒径１０μｍとなるよう粉砕し、活物質の担持体となる炭素質材料粉末を得た。次に得られた炭素質材料粉末９５質量部に負極バインダーとしてメタアクリル酸アルキルエステル−ブタジエン共重合体ラテックスを固形分で５質量部となるように加え、さらに湿潤剤として水を合剤中の含有水分率が１５％となるように加え、これらを混合して湿潤合剤とした。(Example 2)
First, a novolac resin is baked at 950 ° C. in a nitrogen atmosphere, and further heated at 2000 ° C. to carbonize it, and then pulverized to an average particle size of 10 μm to form a carbonaceous material that becomes an active material carrier A material powder was obtained. Next, to 95 parts by mass of the obtained carbonaceous material powder, a methacrylic acid alkyl ester-butadiene copolymer latex is added as a negative electrode binder to a solid content of 5 parts by mass, and water is added as a wetting agent to the mixture. They were added so that the moisture content was 15%, and these were mixed to obtain a wet mixture.

この湿潤合剤を、目開きが直径０．４ｍｍのスクリーンを備えた押出し造粒機により押出し造粒を行った。このとき、押出される造粒合剤を実施例１と同様の流動乾燥機に自然落下させ、乾燥機炉温度８０℃にて流動乾燥を行った。
このようにして乾燥した造粒合剤３ｋｇを篩にかけて顆粒合剤とし、粒度の確認を行った。また、容積５００ｍＬの容器にこの顆粒合剤を収納し、嵩密度の測定を行った。This wet mixture was subjected to extrusion granulation by an extrusion granulator equipped with a screen having an aperture of 0.4 mm in diameter. At this time, the granulated mixture to be extruded was naturally dropped into the same fluidized dryer as in Example 1, and fluidized drying was performed at a dryer furnace temperature of 80 ° C.
The granulated mixture 3 kg dried in this way was sieved to obtain a granular mixture, and the particle size was confirmed. Moreover, this granule mixture was accommodated in the container of capacity 500mL, and the bulk density was measured.

上記により篩い分けした７１０μｍ〜１８０μｍの顆粒合剤を質量０．２ｇ、厚さ０．７ｍｍ、外径１５ｍｍのペレット状に成形し、これを１００℃−７６０ｍＨｇで減圧乾燥し、負極体２８を作製した。  The granular mixture of 710 μm to 180 μm sieved as described above is formed into pellets having a mass of 0.2 g, a thickness of 0.7 mm, and an outer diameter of 15 mm, and dried under reduced pressure at 100 ° C. to 760 mHg to produce anegative electrode body 28. did.

次に、得られた負極体を用いて図５に示す電池を作製した。２１は厚さ０．２５ｍｍのステンレス鋼からなる正極容器であり、この容器２１の内面にはステンレス製の正極集電体２２が内接されている。さらに正極容器２１内には、正極体２３が収納されている。この正極体２３は、Ｖ₂Ｏ₅粉末９０質量部と人造黒鉛１０質量部を混合した後、ポリテトラフルオロエチレン５質量部を混合し、厚さ０．９ｍｍに加圧成形したものである。Next, a battery shown in FIG. 5 was produced using the obtained negative electrode body.Reference numeral 21 denotes a positive electrode container made of stainless steel having a thickness of 0.25 mm. A stainless steel positive electrodecurrent collector 22 is inscribed on the inner surface of thecontainer 21. Further, apositive electrode body 23 is accommodated in thepositive electrode container 21. Thispositive electrode body 23 is obtained by mixing 90 parts by mass of V₂ O₅ powder and 10 parts by mass of artificial graphite, then mixing 5 parts by mass of polytetrafluoroethylene, and press-molding to a thickness of 0.9 mm.

また、正極体２３の上にはポリプロピレン不織布からなるセパレータ２４が設置され、セパレータ２４にはプロピレンカーボネートに過塩素酸リチウムを０．７モル／Ｌの濃度で溶解した電解液が保持されている。さらに、上記セパレータ２４の上面には、前記により製造した負極体２８が配置されている。図中、２５は厚さ０．２５ｍｍのステンレス鋼からなる負極封口体であり、封口板２５の内面には負極集電体２６が内接されており、この集電体２６を含む負極封口板２５の内面に金属リチウム２７が圧着されている。  In addition, aseparator 24 made of a polypropylene non-woven fabric is installed on thepositive electrode body 23, and theseparator 24 holds an electrolytic solution in which lithium perchlorate is dissolved in propylene carbonate at a concentration of 0.7 mol / L. Furthermore, thenegative electrode body 28 manufactured as described above is disposed on the upper surface of theseparator 24. In the figure,reference numeral 25 denotes a negative electrode sealing body made of stainless steel having a thickness of 0.25 mm. A negative electrodecurrent collector 26 is inscribed on the inner surface of the sealingplate 25, and a negative electrode sealing plate including thecurrent collector 26 is included.Metal lithium 27 is pressure-bonded to the inner surface of 25.

正極容器２１の開口部には、パッキング２９を介して負極封口板２５が嵌合されており、正極容器２１のカシメ加工により、正極容器２１および負極封口板２５内に、正極体２３、負極体２８、電解液、セパレータ２４などの発電要素が密閉されている。  A negativeelectrode sealing plate 25 is fitted into the opening of thepositive electrode container 21 via a packing 29, and thepositive electrode body 23 and the negative electrode body are placed in thepositive electrode container 21 and the negativeelectrode sealing plate 25 by caulking of thepositive electrode container 21. 28, the power generation elements such as the electrolytic solution and theseparator 24 are sealed.

上記により、厚さ２．５ｍｍ、外径２０ｍｍのコイン形電池を組み立てた。その後、エージングにより、金属リチウム２７を負極合剤２８にドープせしめ、非水電解液二次電池を作製した。  As described above, a coin-shaped battery having a thickness of 2.5 mm and an outer diameter of 20 mm was assembled. Thereafter,metal lithium 27 was doped into thenegative electrode mixture 28 by aging to produce a non-aqueous electrolyte secondary battery.

（比較例２）
押出し造粒までの工程を実施例２と全く同様に行った。この押出し後の造粒合剤３ｋｇを、１５ｃｍ×１０ｃｍのステンレス製金網に各１ｋｇずつに分けて載置し、これを炉温度８０℃の乾燥炉へ１６時間入れて保管し、水分を蒸発させた。
このようにして乾燥した造粒合剤３ｋｇを篩にかけて顆粒合剤とし、粒度の確認を行った。また、容積５００ｍＬの容器にこの顆粒合剤を収納し、嵩密度の測定を行った。(Comparative Example 2)
The process up to extrusion granulation was carried out in exactly the same manner as in Example 2. 3 kg of the granulated mixture after extrusion is placed on a 15 cm × 10 cm stainless steel wire mesh, divided into 1 kg each, stored in a drying furnace at a furnace temperature of 80 ° C. for 16 hours, and the moisture is evaporated. It was.
The granulated mixture 3 kg dried in this way was sieved to obtain a granular mixture, and the particle size was confirmed. Moreover, this granule mixture was accommodated in the container of capacity 500mL, and the bulk density was measured.

上記の顆粒合剤を用い、実施例２と同様の方法により図５に示す電池を作製した。
上記実施例２および比較例２において測定した粒度分布状態および嵩密度の結果を以下の表４に示す。

A battery shown in FIG. 5 was produced in the same manner as in Example 2 using the above granule mixture.
The results of the particle size distribution state and the bulk density measured in Example 2 and Comparative Example 2 are shown in Table 4 below.

表４に示されるように、実施例２で作製した負極顆粒合剤は、粒径が３５５μｍを中心に揃っており、バラツキが少ない。これに対して比較例２で得られた負極顆粒合剤は広範囲の粒径分布となっていることがわかる。また、嵩密度も実施例２の場合は低下していることがわかる。  As shown in Table 4, the negative electrode granule mixture produced in Example 2 has a uniform particle size centered at 355 μm and has little variation. In contrast, it can be seen that the negative electrode granule mixture obtained in Comparative Example 2 has a wide particle size distribution. In addition, it can be seen that the bulk density is lowered in the case of Example 2.

次に、実施例２および比較例２で作製した電池１００個を用い、放電抵抗２．７ｋΩで連続放電を実施した。その後、充電電圧３．４Ｖ、保護抵抗１００Ωにて４８時間の充電を行い、再度２．７ｋΩで連続放電を実施した。その評価結果を表５に示す。

Next, 100 batteries produced in Example 2 and Comparative Example 2 were used, and continuous discharge was performed with a discharge resistance of 2.7 kΩ. Thereafter, charging was performed for 48 hours at a charging voltage of 3.4 V and a protective resistance of 100Ω, and continuous discharge was performed again at 2.7 kΩ. The evaluation results are shown in Table 5.

上記表５に示すように、実施例２の電池では、放電性能が比較例２の電池に比べ安定し、放電容量のバラツキが少ないことがわかる。これは、顆粒合剤の粒径が揃って安定したことにより、顆粒合剤をペレット状に成形する際、質量のバラツキが減少したことによるものである。  As shown in Table 5 above, it can be seen that the discharge performance of the battery of Example 2 is more stable than that of the battery of Comparative Example 2, and there is little variation in discharge capacity. This is because the variation in mass was reduced when the granule mixture was formed into pellets due to the uniform particle size of the granule mixture.

また、実施例２および比較例２で作製したペレット状の負極体を２０個用いてその強度を測定した。その結果を表６に示す。なお、測定方法は、外径１６ｍｍ、内径１４ｍｍの円柱にペレット状負極体を載せ、直径５ｍｍの加圧棒で上部より押し、ペレット状負極体が破壊するまでの強度を測定する方法である。

Moreover, the strength was measured using 20 pellet-shaped negative electrode bodies produced in Example 2 and Comparative Example 2. The results are shown in Table 6. The measuring method is a method in which a pellet-shaped negative electrode body is placed on a cylinder having an outer diameter of 16 mm and an inner diameter of 14 mm, and is pressed from above with a pressure bar having a diameter of 5 mm, and the strength until the pellet-shaped negative electrode body is broken is measured.

上記表６に示されるように、実施例２のペレット状負極体では強度が向上し、バラツキも減少していることがわかる。これは、流動乾燥方式を用いたことにより合剤の嵩密度が低下し、それによって成形後における合剤強度が向上した結果である。  As shown in Table 6 above, it can be seen that the pellet-like negative electrode body of Example 2 has improved strength and reduced variation. This is a result of the decrease in bulk density of the mixture due to the use of the fluidized drying method, thereby improving the strength of the mixture after molding.

上記実施例ではコイン形二酸化マンガンリチウム電池を用いて説明したが、この限りではない。造粒後に乾燥工程を有するすべての電極合剤の製造に本発明は有効であり、またかかる電極合剤を用いるすべての電池で実施可能である。また、電極については、上記実施例では正極について説明したが、負極についても同様であつて、造粒後に乾燥する必要のあるすべての負極合剤の製造方法に適用でき、例えば、リチウムイオンを吸蔵放出可能な負極材料を用いた負極合剤等を挙げることができる。  In the above embodiment, the coin type lithium manganese dioxide battery has been described. However, the present invention is not limited to this. The present invention is effective in the production of all electrode mixtures having a drying step after granulation, and can be carried out in all batteries using such an electrode mixture. As for the electrode, the positive electrode has been described in the above embodiment, but the same applies to the negative electrode, and it can be applied to all methods for producing a negative electrode mixture that needs to be dried after granulation. Examples include a negative electrode mixture using a releasable negative electrode material.

本発明の正極合剤製造方法の一実施例を示す工程図。Process drawing which shows one Example of the positive mix manufacturing method of this invention.本発明で用いる乾燥方法の実施態様を示す図。The figure which shows the embodiment of the drying method used by this invention.コイン形リチウム電池の概略断面図。1 is a schematic cross-sectional view of a coin-type lithium battery.従来の正極合剤の製造方法を示す工程図。Process drawing which shows the manufacturing method of the conventional positive mix.コイン型非水電解液二次電池の概略断面図。The schematic sectional drawing of a coin type nonaqueous electrolyte secondary battery.

符号の説明Explanation of symbols

１…負極封口板、２…負極、３…セパレータ、４…正極体、５…パッキング、６…正極容器、１１…押出し造粒機、１２…流動乾燥機、１３…被乾燥物挿入塔、１４…ファン室、１５…温風通路、１６…ヒーター、１７…押出し合剤、２１…正極容器、２２…正極集電体、２３…正極体、２４…セパレータ、２５…負極封口板、２６…負極集電体、２７…金属リチウム、２８…負極体、２９…パッキング。

DESCRIPTION OF SYMBOLS 1 ... Negative electrode sealing plate, 2 ... Negative electrode, 3 ... Separator, 4 ... Positive electrode body, 5 ... Packing, 6 ... Positive electrode container, 11 ... Extrusion granulator, 12 ... Fluid dryer, 13 ... Dried object insertion tower, 14 DESCRIPTION OF SYMBOLS ... Fan chamber, 15 ... Warm air passage, 16 ... Heater, 17 ... Extrusion mixture, 21 ... Positive electrode container, 22 ... Positive electrode collector, 23 ... Positive electrode body, 24 ... Separator, 25 ... Negative electrode sealing plate, 26 ... Negative electrodeCurrent collector 27...Metallic lithium 28.Negative electrode body 29. Packing.

Claims (3)

Translated fromJapanese

正極作用物質または負極作用物質を導電剤および結着剤と混合し、これを押出し方式で造粒し、さらに乾燥、分級した後成形する電池正極合剤または負極合剤の製造方法において、上記乾燥工程を流動乾燥方式で行うことを特徴とする電池正極合剤または負極合剤の製造方法。  In the method for producing a battery positive electrode mixture or negative electrode mixture, a positive electrode active material or a negative electrode active material is mixed with a conductive agent and a binder, granulated by an extrusion method, further dried, classified and then molded. A process for producing a battery positive electrode mixture or negative electrode mixture, wherein the step is performed by a fluidized drying method. 乾燥工程が、押出し造粒機から押出された造粒合剤を温風または熱風が吹き上げている流動乾燥機中に自然落下させて流動させながら乾燥させる方法である請求項１記載の電池正極合剤または負極合剤の製造方法。  The battery positive electrode composite according to claim 1, wherein the drying step is a method of drying the granulated mixture extruded from the extrusion granulator while allowing it to fall naturally in a fluidized dryer in which hot air or hot air is blown up and flow. For producing an agent or a negative electrode mixture. 請求項１記載の製造方法で製造した正極合剤または負極合剤を正極または負極として用いたことを特徴とする非水電解液電池。

A non-aqueous electrolyte battery using the positive electrode mixture or the negative electrode mixture manufactured by the manufacturing method according to claim 1 as a positive electrode or a negative electrode.

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