JP2009026562A - Electrode substrate for battery, electrode for battery, and battery - Google Patents
Electrode substrate for battery, electrode for battery, and battery Download PDFInfo
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
Description
本発明は、電池用電極基材、この基材を使用した電池用電極、及びこの電極を使用した電池に関する。特に、アルカリ二次電池の電極に使用することにより、電池容量及び放電特性の向上を図ることができる電極基材に関する。 The present invention relates to a battery electrode substrate, a battery electrode using the substrate, and a battery using the electrode. In particular, the present invention relates to an electrode base material that can improve battery capacity and discharge characteristics when used for an electrode of an alkaline secondary battery.
アルカリ二次電池は、信頼性が高く、長寿命であり、小型軽量化が可能などの特徴があるため、携帯用、移動用、産業用機器の電源として広く利用されている。代表的なアルカリ二次電池としては、ニッケル‐水素電池が挙げられ、エンジンとモータとを組み合わせたハイブリッド電気自動車（HEV）の電源として採用されている。 Alkaline secondary batteries are widely used as power sources for portable, mobile, and industrial devices because of their high reliability, long life, and characteristics that can be reduced in size and weight. A typical alkaline secondary battery is a nickel-hydrogen battery, which is used as a power source for a hybrid electric vehicle (HEV) that combines an engine and a motor.
現在、ニッケル‐水素電池やニッケル‐カドミウム電池等のアルカリ二次電池の電極に使用されている電極基材（集電体）は、正極では三次元網状構造を有する発泡状ニッケル基材が主流になっている。しかし、発泡状ニッケル基材は、発泡状ウレタンを材料として使用しているので、厚みに制限があり、薄くすることが難しい。そのため、電池の高出力化のために薄い電極を作製することが困難である。また、発泡状ニッケル基材は、所定の強度を維持するためにニッケルの使用量を減らすことが難しく、材料コストが高くなる欠点もある。 At present, the electrode substrate (current collector) used for the electrodes of alkaline secondary batteries such as nickel-hydrogen batteries and nickel-cadmium batteries is mainly a foamed nickel substrate having a three-dimensional network structure in the positive electrode. It has become. However, since the foamed nickel base material uses foamed urethane as a material, the thickness is limited and it is difficult to reduce the thickness. Therefore, it is difficult to produce a thin electrode for increasing the output of the battery. In addition, the foamed nickel base material has a drawback that it is difficult to reduce the amount of nickel used to maintain a predetermined strength, and the material cost is increased.
そこで、近年、不織布の繊維表面にニッケルめっきを施した電池用電極基材の開発が進められている。不織布は発泡状ウレタンに比べて厚さの自由度が高く、電極基材を薄くすることが可能である。また、電極基材の内部に不織布の繊維をそのまま骨格として残すことで、ニッケルの使用量を減らすことによる強度の低下を抑制できる。さらに、不織布を使用することで、孔径の小さい電極基材を作製することも容易である。孔径の小さい電極基材は、活物質と電極基材との距離が短くなり、集電効率が高くなる傾向がある。 Thus, in recent years, development of battery electrode base materials in which the surface of the nonwoven fabric is nickel-plated has been promoted. Nonwoven fabrics have a higher degree of freedom in thickness than foamed urethane, and the electrode substrate can be made thinner. Further, by leaving the non-woven fiber as a skeleton as it is inside the electrode substrate, it is possible to suppress a decrease in strength caused by reducing the amount of nickel used. Furthermore, it is easy to produce an electrode substrate having a small pore diameter by using a nonwoven fabric. An electrode base material with a small pore diameter tends to shorten the distance between the active material and the electrode base material and increase the current collection efficiency.
このような不織布を用いた電極基材に関する技術が、例えば特許文献１〜４に開示されている。いずれの文献も、電池性能の向上を図るため、電極基材の構成要素を種々規定している。 The technique regarding the electrode base material using such a nonwoven fabric is disclosed by patent documents 1-4, for example. In any document, in order to improve battery performance, various constituent elements of the electrode base material are defined.
特許文献１には、繊維径3.5μm（繊度0.4dTex相当）の樹脂繊維から成り、坪量（繊維の目付量）80g／m2、厚さ0.56mmの不織布を用いた電極基材が記載されている。 Patent Document 1 describes an electrode base material using a nonwoven fabric having a fiber diameter of 3.5 μm (equivalent to a fineness of 0.4 dTex), a basis weight (fiber weight per unit area) of 80 g / m 2 , and a thickness of 0.56 mm. ing.
特許文献２には、繊度1.2dTexの樹脂繊維から成り、面密度（繊維の目付量）65g／m2、厚さ0.5mmの不織布を用いた電極基材が記載されている。また、この不織布の空隙率は86％である。 Patent Document 2 describes an electrode base material made of a nonwoven fabric having a surface density (fiber weight per unit area) of 65 g / m 2 and a thickness of 0.5 mm, which is made of resin fibers having a fineness of 1.2 dTex. Moreover, the porosity of this nonwoven fabric is 86%.
特許文献３には、繊度6.6dTexの樹脂繊維から成り、繊維の目付量100g／m2、厚さ0.8mmの不織布を用いた電極基材が記載されている。また、この不織布の空隙率は86％である。 Patent Document 3 describes an electrode base material made of a non-woven fabric made of resin fibers having a fineness of 6.6 dTex and having a fiber basis weight of 100 g / m 2 and a thickness of 0.8 mm. Moreover, the porosity of this nonwoven fabric is 86%.
特許文献４には、繊度6.6dTexの樹脂繊維と繊度0.8dTexの樹脂繊維とから成り、繊維の目付量70g／m2、厚さが0.5mmの不織布を用いた電極基材が記載されている。また、この不織布の空隙率は82％である。 Patent Document 4 describes an electrode base material using a non-woven fabric composed of resin fibers having a fineness of 6.6 dTex and resin fibers having a fineness of 0.8 dTex and having a basis weight of 70 g / m 2 and a thickness of 0.5 mm. . The non-woven fabric has a porosity of 82%.
しかし、最近では、アルカリ二次電池の更なる高容量化、高出力化が求められており、従来の不織布を用いた電極基材では、十分な電池容量及び放電特性を確保することが難しく、その要求に応えることができなかった。 However, recently, there has been a demand for further increase in capacity and output of alkaline secondary batteries, and it is difficult to ensure sufficient battery capacity and discharge characteristics with conventional electrode base materials using nonwoven fabrics. I was unable to meet that demand.
ところで、電池容量は電極基材に充填される活物質の充填量に依存し、放電特性は電極基材の集電効率や電気抵抗に左右される。また、活物質の充填量を多くするには、電極基材の多孔度を大きくする必要がある。 By the way, the battery capacity depends on the amount of the active material filled in the electrode base material, and the discharge characteristics depend on the current collection efficiency and electric resistance of the electrode base material. Moreover, in order to increase the filling amount of the active material, it is necessary to increase the porosity of the electrode substrate.
特許文献１〜４に記載の電極基材は、不織布の繊維の目付量が多く、このような不織布を用いた電極基材は、電極基材の孔径が小さくなり過ぎる問題がある。そのため、電極基材の多孔度が十分に大きくても、電極基材に活物質を充填して電極を作製する工程において、活物質の充填率が低くなるので、十分な電池容量を確保できない。また、ニッケルのめっき量が記載されている文献からすると、電極基材に対するニッケルの目付量が少ない。そのため、電極基材の電気抵抗が高くなるので、出力電圧が低く、十分な放電特性を確保できない。 The electrode base materials described in Patent Documents 1 to 4 have a large amount of nonwoven fabric fibers, and the electrode base material using such a nonwoven fabric has a problem that the pore diameter of the electrode base material becomes too small. Therefore, even when the porosity of the electrode substrate is sufficiently large, the filling rate of the active material is reduced in the step of manufacturing the electrode by filling the electrode substrate with the active material, so that a sufficient battery capacity cannot be ensured. Further, from the literature describing the amount of nickel plating, the basis weight of nickel relative to the electrode substrate is small. Therefore, since the electrical resistance of the electrode base material is increased, the output voltage is low and sufficient discharge characteristics cannot be ensured.
本発明は、上記事情に鑑みてなされたものであり、その目的の一つは、電池容量及び放電特性の向上を図ることができる電池用電極基材、及び電池用電極を提供することにある。 The present invention has been made in view of the above circumstances, and one of its purposes is to provide a battery electrode substrate and a battery electrode that can improve battery capacity and discharge characteristics. .
本発明の他の目的は、電池容量が高く且つ放電特性に優れる電池を提供することにある。 Another object of the present invention is to provide a battery having a high battery capacity and excellent discharge characteristics.
本発明は、樹脂繊維から成る不織布の繊維表面に金属の被覆層を有する電池用電極基材である。そして、前記不織布は、繊維の繊度が1dTex以上7dTex以下であり、繊維の目付量が25g／m2以上60g／m2以下である。また、この不織布は、熱処理が施され、熱処理後の厚さが0.5mm以上1.0mm以下である。 The present invention is a battery electrode substrate having a metal coating layer on the surface of a nonwoven fabric made of resin fibers. The nonwoven fabric has a fiber fineness of 1 dTex or more and 7 dTex or less, and a fiber basis weight of 25 g / m 2 or more and 60 g / m 2 or less. Moreover, this nonwoven fabric is heat-processed and the thickness after heat processing is 0.5 mm or more and 1.0 mm or less.
まず、繊維の繊度をこの範囲にすることで、上記範囲の目付量で不織布を作製した際に所定の厚さの不織布を作製し易い。繊維の繊度が1dTex未満であると、不織布の厚さが薄くなり易く、電極に適した厚さの電極基材を得ることが難しい。また、繊維の繊度が1dTex未満であると、孔径が小さくなり過ぎて、電極作製時の活物質の充填が困難になる。繊維の繊度が7dTex超であると、孔径が大きくなり過ぎて、電極基材の比表面積（単位体積あたりの表面積）が小さくなり、電池容量のばらつきや出力電圧の低下を招き易い。より好ましい繊維の繊度は2dTex以上7dTex以下である。 First, by setting the fineness of the fiber within this range, it is easy to produce a nonwoven fabric having a predetermined thickness when the nonwoven fabric is produced with the basis weight within the above range. If the fiber fineness is less than 1 dTex, the thickness of the nonwoven fabric tends to be thin, and it is difficult to obtain an electrode substrate having a thickness suitable for the electrode. Further, if the fineness of the fiber is less than 1 dTex, the pore diameter becomes too small, and it becomes difficult to fill the active material during electrode production. When the fineness of the fiber is more than 7 dTex, the pore diameter becomes too large, the specific surface area (surface area per unit volume) of the electrode base material becomes small, and it tends to cause variation in battery capacity and decrease in output voltage. A more preferable fiber fineness is 2 dTex or more and 7 dTex or less.
次に、繊維の目付量をこの範囲にすることで、電極基材の多孔度が大きくなると共に電極基材の孔径が小さくなり過ぎず、電池容量を高くすることができる。繊維の目付量が25g／m2未満であると、不織布の厚さが薄くなり易く、電極に適した厚さの電極基材を得ることが難しい。繊維の目付量が60g／m2超であると、多孔度が小さくなり、電池容量が低くなる。より好ましい繊維の目付量は30g／m2以上50g／m2以下である。 Next, by setting the fiber basis weight within this range, the porosity of the electrode base material is increased and the pore diameter of the electrode base material is not excessively reduced, so that the battery capacity can be increased. If the basis weight of the fiber is less than 25 g / m 2 , the nonwoven fabric tends to be thin, and it is difficult to obtain an electrode substrate having a thickness suitable for the electrode. When the basis weight of the fiber is more than 60 g / m 2 , the porosity becomes small and the battery capacity becomes low. A more preferable basis weight of the fiber is 30 g / m 2 or more and 50 g / m 2 or less.
次に、不織布の厚さをこの範囲にすることで、電極を作製する際の圧延により被覆層が損傷することを抑制ができる。ここで、不織布の厚さの調整は熱処理により行う。熱処理の温度と時間を調節することで、不織布の厚さを調整することが可能であり、熱処理時間が長くなるほど不織布の厚さが薄くなる傾向がある。不織布をロール等により加圧して調厚した場合、その後の不織布に金属を被覆する工程において、調厚前の厚さに戻ることがあり、調厚の効果が得られ難い。熱処理後の厚さが0.5mm未満であると、電極に適した厚さの電極基材を得ることが難しい。熱処理後の厚さが1.0mm超であると、電極基材に活物質を充填した電極を圧延処理する際に、被覆層が変形して損傷し、出力電圧の低下や耐久性の低下を招く虞がある。より好ましい熱処理後の厚さは0.7mm以上0.9mm以下である。 Next, by setting the thickness of the nonwoven fabric within this range, it is possible to suppress damage to the coating layer due to rolling when the electrode is manufactured. Here, the thickness of the nonwoven fabric is adjusted by heat treatment. By adjusting the temperature and time of the heat treatment, the thickness of the nonwoven fabric can be adjusted. The longer the heat treatment time, the thinner the nonwoven fabric tends to be. When the nonwoven fabric is pressurized and adjusted with a roll or the like, in the subsequent step of coating the nonwoven fabric with metal, the thickness may return to the thickness before the thickness adjustment, and it is difficult to obtain the effect of the thickness adjustment. If the thickness after heat treatment is less than 0.5 mm, it is difficult to obtain an electrode substrate having a thickness suitable for the electrode. When the thickness after heat treatment is more than 1.0 mm, the coating layer is deformed and damaged when rolling an electrode filled with an active material on the electrode substrate, resulting in a decrease in output voltage and durability. There is a fear. More preferably, the thickness after heat treatment is 0.7 mm or more and 0.9 mm or less.
本発明のより好ましい形態は、前記繊維が、融点の異なる２種以上の樹脂から成る複合繊維である。 In a more preferred embodiment of the present invention, the fiber is a composite fiber made of two or more resins having different melting points.
熱処理により複合繊維の融点の低い樹脂成分を溶融させ、複合繊維同士を交差箇所で融着させることで、不織布の強度が高くなり、強固な骨格を有する電極基材とすることができる。複合繊維の構造は、低融点の樹脂が繊維の外側に位置する構造が好ましく、例えば芯成分が高融点樹脂から成り、鞘成分が低融点樹脂から成る芯鞘構造が挙げられる。また、繊維の断面形状は、特に制限がなく、半月状、三日月状、偏心状であってもよい。 By melting the resin component having a low melting point of the conjugate fiber by heat treatment and fusing the conjugate fibers at the intersection, the strength of the nonwoven fabric is increased and an electrode substrate having a strong skeleton can be obtained. The structure of the composite fiber is preferably a structure in which a low melting point resin is located outside the fiber. For example, a core-sheath structure in which the core component is made of a high melting point resin and the sheath component is made of a low melting point resin can be mentioned. The cross-sectional shape of the fiber is not particularly limited, and may be a half moon shape, a crescent shape, or an eccentric shape.
さらに、複合繊維を構成する成分として、ポリエチレン及びポリプロピレンを含むことが好ましい。 Furthermore, it is preferable that polyethylene and polypropylene are included as components constituting the composite fiber.
これら樹脂は、耐薬品性、耐アルカリ性に優れており、電極基材の材料に好適である。上記した芯鞘構造を有する複合繊維の場合、芯成分がポリプロピレン、鞘成分がポリエチレンから成る複合繊維が挙げられる。また、芯成分がポリプロピレン、鞘成分がポリエチレンから成る複合繊維を用いる場合、熱処理の温度を110〜140℃とすることが好ましい。 These resins are excellent in chemical resistance and alkali resistance, and are suitable as materials for electrode substrates. In the case of the composite fiber having the above-described core-sheath structure, a composite fiber in which the core component is made of polypropylene and the sheath component is made of polyethylene can be mentioned. Moreover, when using the composite fiber which a core component consists of polypropylene and a sheath component uses polyethylene, it is preferable that the temperature of heat processing shall be 110-140 degreeC.
本発明のより好ましい形態は、前記金属が、ニッケル、クロム、銅、鉄、コバルト、アルミニウム、チタン、亜鉛、及びこれら金属のいずれかを主体とする合金からなる群から選択される１種以上である。 In a more preferred embodiment of the present invention, the metal is one or more selected from the group consisting of nickel, chromium, copper, iron, cobalt, aluminum, titanium, zinc, and an alloy mainly composed of any of these metals. is there.
これら金属は、耐食性、電気伝導性に優れており、電極基材の材料に好適である。また、リンやホウ素、水素を含有してもよい。被覆層を単一元素の金属で構成する場合、例えばニッケル単体から成る被覆層とすることが挙げられる。被覆層を合金で構成する場合、例えばニッケルとクロムの合金から成る被覆層とすることが挙げられる。 These metals are excellent in corrosion resistance and electrical conductivity, and are suitable for the electrode base material. Moreover, you may contain phosphorus, boron, and hydrogen. When the coating layer is composed of a single element metal, for example, a coating layer made of nickel alone may be used. When the coating layer is made of an alloy, for example, a coating layer made of an alloy of nickel and chromium can be used.
さらに、前記金属を２種以上選択する場合、前記被覆層を２種以上の異なる金属層が積層された多層構造としてもよい。 Further, when two or more kinds of the metals are selected, the coating layer may have a multilayer structure in which two or more different metal layers are laminated.
耐食性により優れる金属層を被覆層の外側に配することで、電極基材の変質及び劣化を防ぎ、長期に亘って安定した性能を有する電極基材を得ることができる。例えば、被覆層を構成する金属にニッケルとクロムを用いて、ニッケル層の外側にクロム層が積層された二層構造の被覆層とすることが挙げられる。 By disposing a metal layer that is more excellent in corrosion resistance on the outside of the coating layer, it is possible to prevent deterioration and deterioration of the electrode substrate and to obtain an electrode substrate having stable performance over a long period of time. For example, nickel and chromium are used as the metal constituting the coating layer, and the coating layer has a two-layer structure in which a chromium layer is laminated outside the nickel layer.
本発明のより好ましい形態は、前記金属の目付量が、150g／m2以上300g／m2以下である。 In a more preferred embodiment of the present invention, the basis weight of the metal is 150 g / m 2 or more and 300 g / m 2 or less.
活物質の充填量及び充填容易性は、不織布の繊維表面に金属の被覆層が形成された後の電極基材の多孔度及び孔径に影響される。金属の目付量をこの範囲にすることで、電極基材の孔径が小さくなり過ぎず、適度な多孔度を有する電極基材を得ることができる。また、電極基材の電気抵抗が低くなり、放電特性（出力電圧）が高くなる効果も期待できる。金属の目付量が150g／m2未満であると、電極基材の電気抵抗が高くなり、出力電圧が低くなる。金属の目付量が300g／m2超であると、多孔度が小さくなり、電池容量が低くなる。なお、高出力化という点では、金属の目付量を多くすることが好ましいと考えられるが、300g／m2を超える場合、電気伝導度がそれほど向上しない上、材料コストが高くなる。より好ましい金属の目付量は、180g／m2以上250g／m2以下である。 The filling amount and ease of filling of the active material are affected by the porosity and pore diameter of the electrode substrate after the metal coating layer is formed on the fiber surface of the nonwoven fabric. By setting the metal basis weight within this range, the electrode substrate having an appropriate porosity can be obtained without excessively reducing the pore diameter of the electrode substrate. Moreover, the electrical resistance of an electrode base material becomes low, and the effect that discharge characteristics (output voltage) become high can also be expected. When the metal areal weight is less than 150 g / m 2 , the electric resistance of the electrode base material is increased and the output voltage is decreased. When the metal areal weight is more than 300 g / m 2 , the porosity becomes small and the battery capacity becomes low. In terms of higher output, it is considered preferable to increase the metal weight per unit area. However, if it exceeds 300 g / m 2 , the electrical conductivity is not improved so much and the material cost is increased. A more preferable metal weight per unit area is 180 g / m 2 or more and 250 g / m 2 or less.
本発明の電池用電極基材は、電極基材の厚さ及び繊維の目付量と金属の目付量から求められる多孔度が、75％以上97％以下であることが好ましい。 The electrode base material for a battery of the present invention preferably has a porosity of 75% or more and 97% or less determined from the thickness of the electrode base material, the basis weight of the fiber, and the basis weight of the metal.
電極基材の多孔度がこのような範囲であることで、電極としたときの活物質の充填量が多くなり、十分な電池容量を確保し易い。より好ましい基材の多孔度は、85％以上95％以下である。なお、基材の多孔度（％）は以下の式により求められる。
本発明の電池用電極基材は、アルカリ二次電池の電極に使用することができる。本発明の電池用電極は、電極基材に活物質が充填されている構成である。例えば、ニッケル‐水素電池の正極では、電極基材に水酸化ニッケルを主体とする活物質が充填されている構成が挙げられる。 The battery electrode substrate of the present invention can be used for an electrode of an alkaline secondary battery. The battery electrode of the present invention has a configuration in which an electrode base material is filled with an active material. For example, a positive electrode of a nickel-hydrogen battery includes a configuration in which an electrode base material is filled with an active material mainly composed of nickel hydroxide.
さらに、電極は、活物質が充填された後に圧延処理が施され、圧延後の電極の厚さ及び繊維の目付量と金属の目付量から求められる空間率が、70％以上95％以下であることが好ましい。 Furthermore, the electrode is subjected to a rolling treatment after being filled with the active material, and the space ratio obtained from the thickness of the electrode after rolling and the basis weight of the fiber and the basis weight of the metal is 70% or more and 95% or less. It is preferable.
圧延処理を施すことで、電極を所定の厚さに調整すると共に、電極の表面を平滑にすることができる。また、本発明者らが検討した結果、電池容量を高めるためには、電極の空間率、つまり活物質を充填可能な空間の割合が重要であることが分かった。電極の空間率がこのような範囲であることで、活物質の充填量が多くなり、十分な電池容量を確保できる。より好ましい電極の空間率は、80％以上95％以下である。なお、電極の空間率（％）は以下の式により求められる。
本発明の電池用電極は、アルカリ二次電池に使用することができる。 The battery electrode of the present invention can be used for an alkaline secondary battery.
水酸化ニッケルを主体とする活物質が充填された本発明の電極（正極）をニッケル‐水素電池に使用する場合、例えばポリオレフィン不織布を親水性処理したセパレータと水素吸蔵合金から成る負極とを用意し、正極と負極との間にセパレータを挟んで電極群を作製する。円筒形電池の場合は、捲回して渦巻状とした電極群を電槽に挿入した後、電解液を注入し、正極の集電端子を蓋部に溶接して、封口を行う。角形電池の場合は、通常、１端子形の正極とし、正極と負極とをセパレータを介して重ねて積層構造とした電極群を電槽に挿入する。 When the electrode (positive electrode) of the present invention filled with an active material mainly composed of nickel hydroxide is used in a nickel-hydrogen battery, for example, a separator obtained by hydrophilic treatment of a polyolefin nonwoven fabric and a negative electrode made of a hydrogen storage alloy are prepared. Then, an electrode group is prepared by sandwiching a separator between the positive electrode and the negative electrode. In the case of a cylindrical battery, a wound and wound electrode group is inserted into a battery case, and then an electrolytic solution is injected, and a positive electrode current collecting terminal is welded to a lid portion to perform sealing. In the case of a rectangular battery, a single-terminal positive electrode is usually used, and an electrode group having a laminated structure in which the positive electrode and the negative electrode are stacked with a separator interposed therebetween is inserted into the battery case.
本発明の電池用電極基材は、電池容量及び放電特性の向上に寄与することができる。 The battery electrode substrate of the present invention can contribute to the improvement of battery capacity and discharge characteristics.
以下、本発明の電池用電極基材及び電極についてより詳しく説明する。 Hereinafter, the battery electrode substrate and the electrode of the present invention will be described in more detail.
不織布を構成する繊維は、耐アルカリ性の繊維であれば特に限定されないが、ポリオレフィン繊維やポリアミド繊維が好適に利用できる。ポリオレフィン繊維を利用する場合、ポリエチレン、ポリプロピレン、これらの混合物、及びこれらの共重合体からなる群から選択される一種を含有することが好ましい。また、繊維は、同群から選択される一種を主成分としてもよいし、一種のみから成るものとしてもよい。繊維の具体例としては、ポリエチレン繊維、ポリプロピレン繊維、ポリエチレンとポリプロピレンの混合繊維の他、芯成分がポリプロピレン、鞘成分がポリエチレンから成る芯鞘構造の複合繊維が挙げられる。 Although the fiber which comprises a nonwoven fabric will not be specifically limited if it is an alkali-resistant fiber, A polyolefin fiber and a polyamide fiber can utilize suitably. When using polyolefin fiber, it is preferable to contain 1 type selected from the group which consists of polyethylene, a polypropylene, these mixtures, and these copolymers. In addition, the fibers may contain one kind selected from the same group as the main component, or may consist of only one kind. Specific examples of the fibers include polyethylene fibers, polypropylene fibers, mixed fibers of polyethylene and polypropylene, and composite fibers having a core-sheath structure in which the core component is polypropylene and the sheath component is polyethylene.
不織布は、例えば、不織布を構成する繊維のウェブを形成した後、繊維同士を結合することにより製造することができる。ウェブは、カード法やエアレイ法、又は紡糸状態から連続的にシート化するメルトブロー法やスパンボンド法のような乾式法、或いは繊維を水に分散し、それを抄きとる湿式法等により製造することができる。また、不織布に水流交絡処理やニードルパンチ処理といった交絡処理を行ったり、繊維同士を融着させる熱処理を行ったりすることで不織布の強度を高めることができる。 A nonwoven fabric can be manufactured by, for example, bonding fibers after forming a web of fibers constituting the nonwoven fabric. The web is manufactured by the card method, air-lay method, dry method such as melt blow method or spun bond method that continuously forms a sheet from the spinning state, or wet method in which fibers are dispersed in water and then drawn. be able to. Moreover, the strength of the nonwoven fabric can be increased by subjecting the nonwoven fabric to entanglement treatment such as hydroentanglement treatment or needle punching treatment or heat treatment for fusing the fibers together.
不織布と金属の被覆層との密着度を向上するために、繊維表面に親水化処理を行ってもよい。親水化処理としては、フッ素処理、コロナ放電処理、スルホン化処理、ビニルモノマーのグラフト重合、親水性樹脂による処理、又は界面活性剤処理等が挙げられる。 In order to improve the adhesion between the nonwoven fabric and the metal coating layer, the fiber surface may be subjected to a hydrophilic treatment. Examples of the hydrophilic treatment include fluorine treatment, corona discharge treatment, sulfonation treatment, graft polymerization of a vinyl monomer, treatment with a hydrophilic resin, or surfactant treatment.
不織布の繊維表面に金属の被覆層を形成するには、公知の電解めっき法を利用することができる。なお、不織布に電解めっきを施す前に、不織布表面、より具体的には不織布を構成する繊維表面に導電性を有する層を形成する。この導電性層を形成する手段として、無電解めっき法、スパッタリング法を利用することができる。以下、不織布の繊維表面にニッケルの被覆層を形成する場合を例に説明する。無電解めっき法を利用する場合、活性化処理として塩化パラジウム溶液中に不織布を浸漬した後、無電解ニッケルめっき浴に不織布を浸漬する。スパッタリング法を利用する場合、ホルダーに不織布を取り付け、不活性ガスを導入しながらホルダーとターゲット（ニッケル）間に直流高電圧を印加して、イオン化した不活性ガスをニッケルに衝突させて、弾き飛ばされたニッケル粒子を繊維表面に堆積させる。ここで、導電性層の形成量は4g/m2ないし9g/m2程度とすることが好ましい。そして、導電性を付与した不織布にニッケルめっき浴を用いて電解ニッケルめっきを施すことで、繊維表面にニッケルの被覆層が形成された電極基材を作製することができる。めっき浴としては、ワット浴、塩化浴、スルファミン酸浴が挙げられる。 In order to form a metal coating layer on the fiber surface of the nonwoven fabric, a known electrolytic plating method can be used. In addition, before electroplating a nonwoven fabric, the layer which has electroconductivity is formed in the nonwoven fabric surface, more specifically the fiber surface which comprises a nonwoven fabric. As means for forming the conductive layer, an electroless plating method or a sputtering method can be used. Hereinafter, a case where a nickel coating layer is formed on the fiber surface of the nonwoven fabric will be described as an example. When the electroless plating method is used, the nonwoven fabric is immersed in a palladium chloride solution as an activation treatment, and then the nonwoven fabric is immersed in an electroless nickel plating bath. When using the sputtering method, attach a non-woven fabric to the holder, apply a DC high voltage between the holder and the target (nickel) while introducing the inert gas, collide the ionized inert gas with nickel, and blow it off. Deposited nickel particles on the fiber surface. Here, the formation amount of the conductive layer is preferably about 4 g / m 2 to 9 g / m 2 . And the electrode base material by which the coating layer of nickel was formed in the fiber surface can be produced by performing electrolytic nickel plating to the nonwoven fabric which provided electroconductivity using a nickel plating bath. Examples of the plating bath include a watt bath, a chloride bath, and a sulfamic acid bath.
ここで、不織布の繊維表面に金属の被覆層を形成するときは、金属の目付量を150g／m2〜300g／m2とすることが好ましい。金属の目付量とは、上記導電性層を形成した場合は導電性層も含めた被覆層の重量を電極基材の面積で除したものであり、電極基材における単位面積当たりの金属の付着量を意味する。金属の目付量が150g／m2未満であると、電極基材の電気伝導度が低下することとなり、電極基材の電気抵抗が高くなる。金属の目付量が150g／m2以上であれば、電気伝導度が高くなり、電気抵抗が低くなる。また、繊維表面に十分な厚さの金属の被覆層が形成されることになり、溶接性に優れる電極基材を得ることができる。但し、金属の目付量が300g／m2超であると、電気伝導度の向上がそれほど見られず、コストメリットが小さい。 Here, when forming a coating layer of metal to the fiber surface of the nonwoven fabric, it is preferable that the basis weight of the metal and 150g / m 2 ~300g / m 2 . When the conductive layer is formed, the metal weight per unit is the weight of the coating layer including the conductive layer divided by the area of the electrode base material, and the amount of metal adhered per unit area on the electrode base material Means quantity. When the metal areal weight is less than 150 g / m 2 , the electric conductivity of the electrode base material is lowered, and the electric resistance of the electrode base material is increased. If the metal areal weight is 150 g / m 2 or more, the electric conductivity is high and the electric resistance is low. In addition, a metal coating layer having a sufficient thickness is formed on the fiber surface, and an electrode substrate having excellent weldability can be obtained. However, if the basis weight of the metal is more than 300 g / m 2 , the electrical conductivity is not so much improved and the cost merit is small.
電極は、上記説明した電極基材に活物質が担持された構成である。活物質としては水酸化ニッケルを主体とするものを用いることができるが、この活物質は、主成分の水酸化ニッケルの他に、水酸化コバルト、オキシ水酸化コバルト、一酸化コバルト、水酸化亜鉛等の他の成分を含むものでもよい。電極は、電極基材に活物質のペーストを充填することにより得ることができる。活物質を充填する前に、活物質の充填量を調整するために電極基材の厚みをロールによって調節（調厚）することが一般的であるが、必要がなければ行わなくてもよい。活物質を充填する手段として、水酸化ニッケルの粉末を混合したペーストに必要に応じて調厚した電極基材を浸漬して圧力を加え、基材表面からペーストを圧入する方法や、前記ペーストを基材表面に吹き付ける方法を利用することができる。このようにして、電極基材の空隙に活物質のペーストを充填した後、通常、乾燥及びロール圧延を行い、電極（正極）が得られる。この電極（正極）には、必要により、集電端子が設けられる。 The electrode has a configuration in which an active material is supported on the electrode base described above. As the active material, a material mainly composed of nickel hydroxide can be used. In addition to the main component of nickel hydroxide, this active material is cobalt hydroxide, cobalt oxyhydroxide, cobalt monoxide, zinc hydroxide. And other components may be included. The electrode can be obtained by filling an electrode substrate with an active material paste. In general, the thickness of the electrode base material is adjusted (thickened) with a roll in order to adjust the filling amount of the active material before filling with the active material. As a means for filling the active material, a method of immersing an electrode base material having a thickness adjusted as necessary in a paste mixed with nickel hydroxide powder and applying pressure from the surface of the base material, or the paste A method of spraying on the surface of the substrate can be used. In this manner, after filling the voids of the electrode base material with the active material paste, drying and roll rolling are usually performed to obtain an electrode (positive electrode). The electrode (positive electrode) is provided with a current collecting terminal as necessary.
＜実施例１＞
（不織布及び電極基材の作製）
表１に示す繊度と繊維の目付量で複数の不織布を作製し、これら不織布を用いて、実施例となる電極基材（試料１〜３）及び比較例となる電極基材（試料４〜８）を作製した。以下、電極基材の作製手順について説明する。
<Example 1>
(Preparation of nonwoven fabric and electrode substrate)
A plurality of nonwoven fabrics are prepared with the fineness and the basis weight of fibers shown in Table 1, and using these nonwoven fabrics, electrode substrates (samples 1 to 3) as examples and electrode substrates (samples 4 to 8) as comparative examples are used. ) Was produced. Hereinafter, the preparation procedure of an electrode base material is demonstrated.
不織布を構成する樹脂繊維には、芯成分がポリプロピレン（融点：165℃）、鞘成分がポリエチレン（融点：110℃）から成る芯鞘構造の複合繊維を用いた。不織布は、カード法を用いて作製し、140℃の熱を加えて厚さを調整した。なお、熱処理時間は不織布毎に変更した。電極基材の厚さは、不織布の厚さと実質的に同じになる。 As the resin fiber constituting the nonwoven fabric, a core-sheath composite fiber having a core component made of polypropylene (melting point: 165 ° C.) and a sheath component made of polyethylene (melting point: 110 ° C.) was used. The nonwoven fabric was produced using the card method, and the thickness was adjusted by applying heat at 140 ° C. In addition, the heat processing time was changed for every nonwoven fabric. The thickness of the electrode substrate is substantially the same as the thickness of the nonwoven fabric.
次に、不織布の繊維表面にニッケルを被覆した。ニッケルの被覆は、無電解めっきと電解めっきとを組み合わせて行った。無電解ニッケルめっきは、塩化第一錫の塩酸水溶液で不織布を処理した後、塩化パラジウムの塩酸水溶液で触媒化し、硫酸ニッケル水溶液に不織布を浸漬して、ニッケルを次亜リン酸ナトリウムにて還元する方法を用いた。この無電解めっきによるニッケルの目付量は5g／m2とした。また、電解めっきは、スルファミン酸浴を用いた。無電解めっきにより繊維表面に導電性層が形成された不織布をめっき浴に浸漬し、不織布を陰極に、ニッケル板を陽極にそれぞれ接続して直流を流して、不織布の繊維表面にニッケルの被覆層を形成した。 Next, nickel was coated on the fiber surface of the nonwoven fabric. The nickel coating was performed by combining electroless plating and electrolytic plating. Electroless nickel plating treats a nonwoven fabric with stannous chloride aqueous hydrochloric acid solution, then catalyzes it with palladium chloride aqueous hydrochloric acid solution, immerses the nonwoven fabric in nickel sulfate aqueous solution, and reduces nickel with sodium hypophosphite The method was used. The basis weight of nickel by this electroless plating was 5 g / m 2 . In addition, a sulfamic acid bath was used for electrolytic plating. A non-woven fabric with a conductive layer formed on the fiber surface by electroless plating is immersed in a plating bath, the non-woven fabric is connected to the cathode, a nickel plate is connected to the anode, and direct current is applied to the surface of the non-woven fabric to provide a nickel coating layer. Formed.
作製した電極基材（試料１〜８）の厚さ、ニッケルの目付量及び多孔度を表１に示す。厚さは加重3g／m2で測定した。基材の多孔度は、基材の厚さ及び繊維の目付量と金属の目付量から上記式１により求めた。なお、繊維密度は0.92（g／cc）とし、ニッケル密度は8.9（g／cc）とした。 Table 1 shows the thickness, the basis weight of nickel, and the porosity of the produced electrode base materials (samples 1 to 8). The thickness was measured at a load of 3 g / m 2 . The porosity of the substrate was determined by the above formula 1 from the thickness of the substrate, the basis weight of the fiber, and the basis weight of the metal. The fiber density was 0.92 (g / cc), and the nickel density was 8.9 (g / cc).
試料１〜３、及び試料５,８は、熱処理後の厚さが0.5mm以上1.0mm以下であった。しかし、試料４,６,７は、熱処理後の厚さが0.5mm未満であった。試料４は、繊維の目付量が少なく、十分な繊維の重なりを形成することができず、薄くなったと考えられる。試料６は、繊維の繊度が小さく、繊維のコシが弱いため厚さを維持することができず、薄くなったと考えられる。試料７は、熱処理時間が長すぎて、熱処理後の厚さが薄くなった。 Samples 1 to 3 and samples 5 and 8 had a thickness after heat treatment of 0.5 mm to 1.0 mm. However, Samples 4, 6, and 7 had a thickness after heat treatment of less than 0.5 mm. It is considered that Sample 4 has a small amount of fibers and cannot form a sufficient overlap of fibers, and is thinned. Sample 6 is thought to be thin because the fineness of the fiber is small and the stiffness of the fiber is weak, so the thickness cannot be maintained. In Sample 7, the heat treatment time was too long, and the thickness after the heat treatment became thin.
（電極の作製）
試料１〜８の電極基材を使用したニッケル‐水素電池の電極１〜８を作製した。以下、電極の作製手順について説明する。
(Production of electrodes)
Electrodes 1-8 of nickel-hydrogen batteries using the electrode base materials of Samples 1-8 were prepared. Hereinafter, a procedure for manufacturing the electrode will be described.
まず、電極基材を幅36mm×長さ100mmに切断し、集電端子を溶接する領域（端から幅36mm×長さ5mmの部分）を押し潰した後、この領域にマスキングを施した。これは、集電端子が溶接される領域に活物質が充填されないようにするためである。電極は、電極基材を活物質ペーストに浸漬する方法を用いて作製した。活物質ペーストは、主活物質としてコバルト被覆水酸化ニッケルの粉末20g、導電助剤として水酸化コバルトの粉末1.5g、増粘剤として濃度が0.5質量％のカルボキシメチルセルロース水溶液6gの割合で混合したものである。この活物質ペーストに電極基材を浸漬し、引き上げ後、表面に付着した活物質ペーストを除去して表面を平滑化して80℃の温度で30分間乾燥させた。乾燥後、電極基材をロールプレス機（20t、ギャップ0.2mm）を用いて圧延し、幅方向の両端を切り落として幅32mmの電極とした。 First, the electrode base material was cut into a width of 36 mm and a length of 100 mm, and a region where the current collector terminal was welded (a portion having a width of 36 mm and a length of 5 mm from the end) was crushed, and then this region was masked. This is to prevent the active material from being filled in the region where the current collecting terminal is welded. The electrode was produced using a method in which the electrode substrate was immersed in the active material paste. The active material paste is a mixture of 20 g of cobalt-coated nickel hydroxide powder as the main active material, 1.5 g of cobalt hydroxide powder as the conductive additive, and 6 g of carboxymethylcellulose aqueous solution with a concentration of 0.5 mass% as the thickener. It is. The electrode base material was dipped in this active material paste, pulled up, the active material paste adhered to the surface was removed, the surface was smoothed, and dried at a temperature of 80 ° C. for 30 minutes. After drying, the electrode base material was rolled using a roll press (20 t, gap 0.2 mm), and both ends in the width direction were cut off to obtain an electrode having a width of 32 mm.
各電極の厚さ、空間率、充填率及び容量密度を表２に示す。電極の空間率は、電極の厚さ及び繊維の目付量と金属の目付量から上記式２により求めた。充填率は、乾燥させた活物質ペーストの密度を予め求めておき、電極の重量から電極基材に充填された活物質の体積を求め、それを電極の空孔体積で除して求めた。ここで、電極の空孔体積は、活物質を充填可能な空間の体積のことであり、電極の見かけの体積から電極の真の体積（電極を構成する材料の体積）を減じて残った体積（空隙）として求めることができる。容量密度は、電極に充填された活物質のうち、水酸化ニッケルの重量に289mAh／gを乗じた後、電極の体積で除して求めた。 Table 2 shows the thickness, space ratio, filling rate, and capacity density of each electrode. The space ratio of the electrode was determined by the above formula 2 from the electrode thickness, the basis weight of the fiber, and the basis weight of the metal. The filling rate was obtained by obtaining the density of the dried active material paste in advance, obtaining the volume of the active material filled in the electrode substrate from the weight of the electrode, and dividing it by the pore volume of the electrode. Here, the pore volume of the electrode is the volume of the space in which the active material can be filled, and the volume left after subtracting the true volume of the electrode (volume of the material constituting the electrode) from the apparent volume of the electrode (Void). The capacity density was obtained by multiplying the weight of nickel hydroxide by 289 mAh / g among the active material filled in the electrode and then dividing by the volume of the electrode.
電極１〜３及び電極８は、容量密度が600mAh／g以上であった。しかし、電極４〜７は、容量密度が低く、500mAh／g未満であった。電極４は、空間率が80％以上であるが、厚さが薄く充填できる活物質の量が少なかった。また、電極４は、電極基材（試料４）の繊維目付量が少なく且つ繊度が大きいため、基材の孔径が大きくなり過ぎて、活物質の保持性が悪く充填率が低下して、容量密度が小さくなったと考えられる。電極５は、電極基材（試料５）の繊維目付量が多いために基材の孔径が小さくなり過ぎて、活物質の充填率が低くなり容量密度が小さくなったと考えられる。電極６は、空間率が70％以下であり且つ厚さが薄く、充填できる活物質の量が少なかった。また、電極６は、電極基材（試料６）の繊度が小さいために基材の孔径が小さくなり過ぎて、活物質の充填率が低くなり容量密度が小さくなったと考えられる。電極７は、厚さが薄く充填できる活物質の量が少なかった。また、電極７の電極基材（試料７）と電極２の電極基材（試料２）の繊度と繊維目付量は同じであるが、電極７の電極基材は薄くし過ぎたため、基材の孔径が小さくなり過ぎて、活物質の充填率が低くなり容量密度が小さくなったと考えられる。 The electrodes 1 to 3 and the electrode 8 had a capacity density of 600 mAh / g or more. However, the electrodes 4 to 7 had a low capacity density of less than 500 mAh / g. The electrode 4 has a space ratio of 80% or more, but has a small amount of active material that can be filled thinly. In addition, since the electrode 4 has a small fiber basis weight and a large fineness of the electrode base material (sample 4), the pore diameter of the base material becomes too large, the retention of the active material is poor, the filling rate is lowered, and the capacity It is thought that the density has decreased. It is considered that the electrode 5 has a large fiber basis weight of the electrode base material (sample 5), so that the pore diameter of the base material becomes too small, the filling rate of the active material becomes low, and the capacity density becomes low. The electrode 6 had a space ratio of 70% or less, a thin thickness, and a small amount of active material that could be filled. Moreover, since the electrode 6 has a small fineness of the electrode base material (sample 6), the pore diameter of the base material is too small, the filling rate of the active material is lowered, and the capacity density is considered to be small. The electrode 7 had a small amount of active material that could be filled thin. Further, although the fineness and the fiber basis weight of the electrode base material of the electrode 7 (sample 7) and the electrode base material of the electrode 2 (sample 2) are the same, the electrode base material of the electrode 7 is too thin. It is considered that the pore diameter was too small, the filling rate of the active material was lowered, and the capacity density was reduced.
（電池の作製）
次に、電極１〜３及び電極８を正極に使用したニッケル‐水素電池を作製し、各電池ついて性能試験を実施し、各電極について評価した。
(Production of battery)
Next, a nickel-hydrogen battery using the electrodes 1 to 3 and the electrode 8 as positive electrodes was produced, a performance test was performed on each battery, and each electrode was evaluated.
また、新たに試料９を作製し、これを電極基材に使用した電極９を作製した。なお、試料９及び電極９の作製手順は、上記説明した作製手順と同じである。そして、この電極９を正極に使用したニッケル‐水素電池を作製して性能試験を実施し、この電極９についても評価した。表３及び表４は試料９及び電極９の仕様である。 Moreover, the sample 9 was newly produced and the electrode 9 which used this for the electrode base material was produced. In addition, the preparation procedure of the sample 9 and the electrode 9 is the same as that described above. And the nickel-hydrogen battery which used this electrode 9 for the positive electrode was produced, the performance test was implemented, and this electrode 9 was also evaluated. Tables 3 and 4 show the specifications of the sample 9 and the electrode 9.
表に示すように、試料９は、熱処理後の厚さが0.5mm以上1.0mm以下であった。また、電極９は、容量密度が600mAh／g以上であった。 As shown in the table, Sample 9 had a thickness after heat treatment of 0.5 mm to 1.0 mm. The electrode 9 had a capacity density of 600 mAh / g or more.
以下、電池の作製手順について説明する。 Hereinafter, a battery manufacturing procedure will be described.
電池は、正極と負極との間にセパレータを挟んで捲回した電極群をSub-Cサイズの電槽に挿入した後、この電槽に電解液を注入し、封口を行うことで作製した。負極には、公知の水素吸蔵合金を用い、セパレータには、親水化処理されたポリエチレン不織布を用いた。また、電解液には、濃度が30質量％の水酸化カリウム水溶液を用いた。 The battery was fabricated by inserting an electrode group wound with a separator between a positive electrode and a negative electrode into a Sub-C size battery case, injecting an electrolyte into the battery case, and sealing the battery. A known hydrogen storage alloy was used for the negative electrode, and a hydrophilic non-woven polyethylene nonwoven fabric was used for the separator. Further, an aqueous potassium hydroxide solution having a concentration of 30% by mass was used as the electrolytic solution.
電極１〜３及び電極８,９を用いた電池をそれぞれ電池１〜３及び電池８,９とし、各電池について性能試験を実施した。なお、試験を行う前に各電池について化成処理を行った。具体的には、0.1Cで充放電を1回行った後、0.2Cで充放電を20回繰り返した。 The batteries using the electrodes 1 to 3 and the electrodes 8 and 9 were designated as batteries 1 to 3 and batteries 8 and 9, respectively, and a performance test was performed on each battery. In addition, before performing a test, chemical conversion treatment was performed for each battery. Specifically, after charging and discharging once at 0.1 C, charging and discharging was repeated 20 times at 0.2 C.
性能試験は、0.2Cで充電し、0.2Cで放電したときの放電容量と放電電圧、及び1Cで充電し、1Cで放電したときの放電容量と放電電圧を調べた。充電はCCΔV方式で行い、計算容量の110％、或いは電圧降下が-5mVになった時点で充電終了とした。放電はCC方式で行い、終止電圧0.8Vになった時点で放電終了とした。 In the performance test, the discharge capacity and discharge voltage when charged at 0.2 C and discharged at 0.2 C, and the discharge capacity and discharge voltage when charged at 1 C and discharged at 1 C were examined. Charging was performed using the CCΔV method, and the charging was terminated when 110% of the calculated capacity or the voltage drop reached -5 mV. Discharge was performed by the CC method, and the discharge was terminated when the final voltage reached 0.8V.
放電容量は、放電開始から終了までの時間と放電電流の積分で求めた値を計算容量で除した値（利用率、単位％）である。また、放電電圧は、電池容量の1／2まで放電したときの電圧を測定して求めた。ここで、計算容量とは、電極に充填された活物質のうち、水酸化ニッケルの重量に289mAh／gを乗じて求めた容量のことである。 The discharge capacity is a value (utilization rate, unit%) obtained by dividing the value obtained by integrating the time from the start to the end of discharge and the discharge current by the calculated capacity. The discharge voltage was determined by measuring the voltage when discharging to 1/2 the battery capacity. Here, the calculated capacity is a capacity obtained by multiplying the weight of nickel hydroxide by 289 mAh / g in the active material filled in the electrode.
また、CCΔV方式の充電とは、一定の電流で充電を行い、所定の時間（容量）まで充電したとき、或いは電圧降下が所定の閾値を超えたときに充電を終了する方式である。CC方式の放電とは、一定の電流で放電を行い、所定の時間（容量）まで放電したとき、或いは放電電圧が所定の閾値を超えたときに放電を終了する方式である。 The CCΔV charging is a method in which charging is performed at a constant current and charging is performed until a predetermined time (capacity) or when the voltage drop exceeds a predetermined threshold. The CC method discharge is a method in which discharge is performed at a constant current and the discharge is terminated when the discharge is performed for a predetermined time (capacity) or when the discharge voltage exceeds a predetermined threshold.
表５に各電池の放電容量及び放電電圧を示す。 Table 5 shows the discharge capacity and discharge voltage of each battery.
電池１〜３は、0.2C及び1Cでの放電容量が95％以上であり、0.2C及び1Cでの放電電圧がそれぞれ1.2V以上及び1.05V以上である。つまり、電極１〜３は、充填された活物質の利用率が高く、出力電圧も高いことが分かる。したがって、実施例に係る電極基材（試料１〜３）は、電池容量及び放電特性の向上に寄与することができる。特に、1Cでの放電電圧が高いので、高出力タイプの電池にも好適に使用することができる。 In batteries 1 to 3, the discharge capacities at 0.2C and 1C are 95% or more, and the discharge voltages at 0.2C and 1C are 1.2V or more and 1.05V or more, respectively. That is, it can be seen that the electrodes 1 to 3 have a high utilization rate of the filled active material and a high output voltage. Therefore, the electrode base materials (samples 1 to 3) according to the examples can contribute to improvement of battery capacity and discharge characteristics. In particular, since the discharge voltage at 1 C is high, it can be suitably used for high output type batteries.
一方、電池８,９は、放電容量及び放電電圧が低い。電極８は、電極基材（試料８）の厚さが厚かったため、圧延して電極とした際に基材の被覆層が損傷し、基材の電気抵抗が増大して、放電容量及び放電電圧が低くなったと考えられる。電極９は、電極基材（試料９）のニッケルの目付量が少ないため、基材の電気抵抗が高く、放電容量及び放電電圧が低くなったと考えられる。 On the other hand, the batteries 8 and 9 have low discharge capacity and discharge voltage. In the electrode 8, since the electrode substrate (sample 8) was thick, when the electrode was rolled to damage the coating layer of the substrate, the electrical resistance of the substrate was increased, and the discharge capacity and discharge voltage were increased. Is considered to be low. Since the electrode 9 has a small basis weight of nickel in the electrode base material (sample 9), it is considered that the base material has a high electric resistance and a low discharge capacity and discharge voltage.
本発明の電池用電極基材、及び電池用電極は、高容量・高出力のアルカリ二次電池に好適に利用することができる。また、本発明の電池は、携帯用、移動用、産業用機器の電源に好適に利用することができる。 The battery electrode base material and battery electrode of the present invention can be suitably used for high capacity and high output alkaline secondary batteries. The battery of the present invention can be suitably used as a power source for portable, mobile and industrial equipment.
Claims (10)
前記不織布は、
繊維の繊度が1dTex以上7dTex以下であり、
繊維の目付量が25g／m2以上60g／m2以下であり、
熱処理が施され、熱処理後の厚さが0.5mm以上1.0mm以下であることを特徴とする電池用電極基材。 A battery electrode base material having a metal coating layer on a fiber surface of a nonwoven fabric made of resin fibers,
The nonwoven fabric is
The fineness of the fiber is 1dTex or more and 7dTex or less,
The basis weight of the fiber is 25 g / m 2 or more and 60 g / m 2 or less,
A battery electrode substrate that is heat-treated and has a thickness of 0.5 mm to 1.0 mm after heat treatment.
圧延後の電極の厚さ及び繊維の目付量と金属の目付量から求められる空間率が、70％以上95％以下であることを特徴とする請求項８に記載の電池用電極。 After the active material is filled, a rolling process is performed,
The battery electrode according to claim 8, wherein the space ratio obtained from the thickness of the electrode after rolling, the basis weight of the fiber and the basis weight of the metal is 70% or more and 95% or less.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120077061A1 (en) * | 2010-09-27 | 2012-03-29 | Hoppecke Batterie Systeme Gmbh | Nickel-Metal Hydride Accumulator |
| JP2013114795A (en) * | 2011-11-25 | 2013-06-10 | Sumitomo Electric Ind Ltd | Electrode using aluminum porous body for collector, and method of manufacturing the same |
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|---|---|---|---|---|
| JPH08203534A (en) * | 1995-01-27 | 1996-08-09 | Mitsubishi Paper Mills Ltd | Manufacture of nickel plated nonwoven electrode substrate |
| JP2006310261A (en) * | 2005-01-14 | 2006-11-09 | Sumitomo Electric Ind Ltd | Current collector and electrode base plate for battery and their manufacturing method |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08203534A (en) * | 1995-01-27 | 1996-08-09 | Mitsubishi Paper Mills Ltd | Manufacture of nickel plated nonwoven electrode substrate |
| JP2006310261A (en) * | 2005-01-14 | 2006-11-09 | Sumitomo Electric Ind Ltd | Current collector and electrode base plate for battery and their manufacturing method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120077061A1 (en) * | 2010-09-27 | 2012-03-29 | Hoppecke Batterie Systeme Gmbh | Nickel-Metal Hydride Accumulator |
| JP2013114795A (en) * | 2011-11-25 | 2013-06-10 | Sumitomo Electric Ind Ltd | Electrode using aluminum porous body for collector, and method of manufacturing the same |
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