JP5034418B2 - Nonaqueous electrolyte secondary battery - Google Patents

Nonaqueous electrolyte secondary battery Download PDF

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JP5034418B2
JP5034418B2 JP2006267921A JP2006267921A JP5034418B2 JP 5034418 B2 JP5034418 B2 JP 5034418B2 JP 2006267921 A JP2006267921 A JP 2006267921A JP 2006267921 A JP2006267921 A JP 2006267921A JP 5034418 B2 JP5034418 B2 JP 5034418B2
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利一 中村
健一郎 細田
政司 伊藤
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Sony Corp
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Description

本発明は、帯状の正極と帯状の負極とセパレータを巻回した巻回電極体を外装材に収納した非水電解質二次電池に係り、更に詳細には、帯状電極に合剤層を有さない領域を設ける場合の巻回電極体構造の改良に関する。   The present invention relates to a non-aqueous electrolyte secondary battery in which a wound electrode body in which a strip-shaped positive electrode, a strip-shaped negative electrode, and a separator are wound is housed in an exterior material. The present invention relates to an improvement of a wound electrode body structure in the case of providing no region.

従来、上述のような非水電解質二次電池において、巻回電極体は、帯状に形成された正極及び負極と、同じく帯状に形成されたセパレータとを有し、これらが負極、セパレータ正極及びセパレータの順に積層され、このように４層に重ね合わせた積層体を適宜の巻数巻回することにより構成されている。
かかる従来の非水電解質二次電池においては、集電体の巻回方向の外周側端部の近傍まで正極又は負極合剤層が形成されていたため、例えば、電池缶が押し潰される等の異常事態が発生したときに、負極の外周側端部がセパレータを突き破ると、その先端部が隣り合う正極の合剤層に接触し、その結果、負極と正極が互いに導通して内部短絡（ショート）が発生することがあった。 Conventionally, in the non-aqueous electrolyte secondary battery as described above, the wound electrode body has a positive electrode and a negative electrode formed in a strip shape, and a separator formed in the same strip shape, and these are a negative electrode, a separator positive electrode and a separator. The layered body is laminated in this order, and the laminated body thus superposed on the four layers is configured by winding an appropriate number of turns.
In such a conventional non-aqueous electrolyte secondary battery, since the positive electrode or negative electrode mixture layer is formed to the vicinity of the outer peripheral side end in the winding direction of the current collector, for example, abnormalities such as the battery can being crushed When a situation occurs, when the outer peripheral end of the negative electrode breaks through the separator, the front end contacts the adjacent positive electrode mixture layer. As a result, the negative electrode and the positive electrode are electrically connected to each other, thereby causing an internal short circuit. May occur.

これに対し、電極の巻回方向の端部において当該端部から一周以上の範囲に亘り合剤層が形成されない集電体露出部を設けることにより、電極がセパレータを突き破って隣り合う電極に接触するようになった場合にも同じ極同士が接触するようにして、内部短絡の発生を防止又は効果的に抑制することができる非水電解質二次電池が提案されている（例えば、特許文献１参照）。
特開２００３−２９７４３２号公報 On the other hand, by providing a current collector exposed portion where a mixture layer is not formed over a range of one or more rounds from the end portion in the winding direction of the electrode, the electrode contacts the adjacent electrode by breaking through the separator. A non-aqueous electrolyte secondary battery that can prevent or effectively suppress the occurrence of an internal short circuit has also been proposed (for example, Patent Document 1). reference).
JP 2003-297432 A

しかしながら、従来の非水電解質二次電池の巻回電極体において、セパレータは正極合剤層と負極合剤層に挟まれた状態で巻回されており、充電の際、正極合剤層と負極合剤層が膨張して厚みが増大すると、特に巻回電極体の外周部近傍（巻回終端近傍）では、セパレータが局所的に引き伸ばされて正極と負極との極間距離が局所的に狭くなり、この狭小部位に充放電に伴ってメタルが集中的に析出し、内部短絡を引き起こすことがあった。
また、この現象は、近時における電池容量増大の要請に伴ってセパレータが薄肉化されている実情を考慮すれば、ますます注意すべき事項である。 However, in the wound electrode body of the conventional nonaqueous electrolyte secondary battery, the separator is wound in a state sandwiched between the positive electrode mixture layer and the negative electrode mixture layer, and at the time of charging, the positive electrode mixture layer and the negative electrode When the mixture layer expands and the thickness increases, particularly in the vicinity of the outer periphery of the wound electrode body (near the winding end), the separator is locally stretched, and the distance between the positive electrode and the negative electrode is locally narrow. As a result, the metal is concentrated in the narrow portion along with charge / discharge, which may cause an internal short circuit.
In addition, this phenomenon is a matter that should be more carefully considered in consideration of the fact that the separator has become thinner with the recent demand for increased battery capacity.

更に、巻回電極体の巻回方向終端部近傍に集電体露出部を設けた非水電解質二次電池では、かかる集電体露出部が、両面であるか片面であるかを問わずにセパレータなどの厚み方向に段差を生ずるので、上記セパレータの引き伸ばしを助長してしまうことがあった。   Furthermore, in the nonaqueous electrolyte secondary battery in which the current collector exposed portion is provided near the winding direction end portion of the wound electrode body, regardless of whether the current collector exposed portion is double-sided or single-sided Since a step is generated in the thickness direction of the separator or the like, the separator may be stretched.

本発明は、このような従来技術の有する課題に鑑みてなされたものであり、その目的とするところは、局所的な極間距離の狭小化を抑制し、内部短絡を抑制してサイクル特性の低下を改善し得る信頼性の高い非水電解質二次電池を提供することにある。   The present invention has been made in view of such problems of the prior art, and the object of the present invention is to suppress local narrowing of the interelectrode distance, suppress internal short circuit, and improve cycle characteristics. An object of the present invention is to provide a highly reliable non-aqueous electrolyte secondary battery capable of improving the deterioration.

本発明者らは、上記目的を達成すべく鋭意検討を重ねた結果、セパレータの厚み方向に段差を発生し得る集電体露出部などを適切に配置することにより、上記目的が達成できることを見出し、本発明を完成するに至った。   As a result of intensive investigations to achieve the above object, the present inventors have found that the above object can be achieved by appropriately arranging a collector exposed portion that can generate a step in the thickness direction of the separator. The present invention has been completed.

即ち、本発明の非水電解質二次電池は、極性の異なる第１電極と第２電極をセパレータを介して巻回して成る巻回電極体と、非水電解質組成物と、これらを収容する外装体を備え、
上記第１電極が、帯状をなす第１電極集電体の内周面に内側第１電極合剤層を有するとともに、その外周面に外側第１電極合剤層を有し、
上記第２電極が、帯状をなす第２電極集電体の内周面に内側第２電極合剤層を有するとともに、その外周面に外側第２電極合剤層を有する、非水電解質二次電池において、
上記巻回電極体は、その巻回中心に対して、上記第１電極が内側で、上記第２電極が外側になるように巻回されており、
上記第２電極が、巻回終端の方向に沿って、上記外側第２電極合剤層を有さない外側第２電極集電体露出部と、上記内側第２電極合剤層及び上記外側第２電極合剤層を有さない両側第２電極集電体露出部を、この順で有し、
上記第１電極が、巻回終端の方向に沿って、上記内側第１電極合剤層を有さない内側第１電極集電体露出部と、上記内側第１電極合剤層及び上記外側第１電極合剤層を有さない両側第１電極集電体露出部を、この順で有し、
上記外側第２電極集電体露出部の始点、上記内側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、ことを特徴とする。 That is, the non-aqueous electrolyte secondary battery of the present invention includes a wound electrode body formed by winding a first electrode and a second electrode having different polarities through a separator, a non-aqueous electrolyte composition, and an exterior housing these. With a body,
The first electrode has an inner first electrode mixture layer on the inner peripheral surface of the first electrode current collector having a strip shape, and an outer first electrode mixture layer on the outer peripheral surface thereof,
The non-aqueous electrolyte secondary, wherein the second electrode has an inner second electrode mixture layer on the inner peripheral surface of the second electrode current collector having a strip shape and an outer second electrode mixture layer on the outer peripheral surface. In batteries,
The wound electrode body is wound such that the first electrode is on the inner side and the second electrode is on the outer side with respect to the winding center,
The second electrode has an outer second electrode current collector exposed portion not having the outer second electrode mixture layer, the inner second electrode mixture layer, and the outer second electrode along the winding end direction. Having both side second electrode current collector exposed portions not having a two-electrode mixture layer in this order,
The first electrode has an inner first electrode current collector exposed portion that does not have the inner first electrode mixture layer, the inner first electrode mixture layer, and the outer first electrode along the winding end direction. Having both side first electrode current collector exposed portions not having one electrode mixture layer in this order,
The start point of the outer second electrode current collector exposed portion, the start point of the inner first electrode current collector exposed portion, the start point of the both side second electrode current collector exposed portion, and the both side first electrode current collector exposed portion Is located on a separate radius of the winding center.

また、本発明の非水電解質二次電池の好適形態は、上記外装体の内周面に、上記第２電極と上記外装体とを電気接続する第２電極リードを有し、
この第２電極リード、上記外側第２電極集電体露出部の始点、上記内側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び両側上記第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、ことを特徴とする。 Moreover, the suitable form of the nonaqueous electrolyte secondary battery of this invention has the 2nd electrode lead which electrically connects the said 2nd electrode and the said exterior body on the internal peripheral surface of the said exterior body,
The second electrode lead, the start point of the outer second electrode current collector exposed portion, the start point of the inner first electrode current collector exposed portion, the start point of the second electrode current collector exposed portion on both sides, and the first side on both sides The starting point of the electrode current collector exposed portion is located on a separate radius of the winding center.

一方、本発明の他の非水電解質二次電池は、極性の異なる第１電極と第２電極をセパレータを介して巻回して成る巻回電極体と、非水電解質組成物と、これらを収容する外装体を備え、
上記第１電極が、帯状をなす第１電極集電体の内周面に内側第１電極合剤層を有するとともに、その外周面に外側第１電極合剤層を有し、
上記第２電極が、帯状をなす第２電極集電体の内周面に内側第２電極合剤層を有するとともに、その外周面に外側第２電極合剤層を有する、非水電解質二次電池において、
上記巻回電極体は、その巻回中心に対して、上記第１電極が内側で、上記第２電極が外側になるように巻回されており、
上記第２電極が、巻回終端の方向に沿って、上記外側第２電極合剤層を有さない外側第２電極集電体露出部と、上記内側第２電極合剤層及び上記外側第２電極合剤層を有さない両側第２電極集電体露出部を、この順で有し、
上記第１電極が、巻回終端の方向に沿って、上記外側第１電極合剤層を有さない外側第１電極集電体露出部と、上記内側第１電極合剤層及び上記外側第１電極合剤層を有さない両側第１電極集電体露出部を、この順で有し、
上記外側第２電極集電体露出部の始点、上記外側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、ことを特徴とする。 On the other hand, another nonaqueous electrolyte secondary battery of the present invention contains a wound electrode body formed by winding a first electrode and a second electrode having different polarities through a separator, a nonaqueous electrolyte composition, and these. With an exterior body
The first electrode has an inner first electrode mixture layer on the inner peripheral surface of the first electrode current collector having a strip shape, and an outer first electrode mixture layer on the outer peripheral surface thereof,
The non-aqueous electrolyte secondary, wherein the second electrode has an inner second electrode mixture layer on the inner peripheral surface of the second electrode current collector having a strip shape and an outer second electrode mixture layer on the outer peripheral surface. In batteries,
The wound electrode body is wound such that the first electrode is on the inner side and the second electrode is on the outer side with respect to the winding center,
The second electrode has an outer second electrode current collector exposed portion not having the outer second electrode mixture layer, the inner second electrode mixture layer, and the outer second electrode along the winding end direction. Having both side second electrode current collector exposed portions not having a two-electrode mixture layer in this order,
The first electrode has an outer first electrode current collector exposed portion that does not have the outer first electrode mixture layer, the inner first electrode mixture layer, and the outer first electrode along the winding end direction. Having both side first electrode current collector exposed portions not having one electrode mixture layer in this order,
The start point of the outer second electrode current collector exposed portion, the start point of the outer first electrode current collector exposed portion, the start point of the both side second electrode current collector exposed portion, and the both side first electrode current collector exposed portion Is located on a separate radius of the winding center.

また、本発明の他の非水電解質二次電池の好適形態は、上記外装体の内周面に、上記第２電極と上記外装体とを電気接続する第２電極リードを有し、
この第２電極リード、上記外側第２電極集電体露出部の始点、上記外側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び両側上記第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、ことを特徴とする。 Moreover, the suitable form of the other nonaqueous electrolyte secondary battery of this invention has the 2nd electrode lead which electrically connects the said 2nd electrode and the said exterior body in the internal peripheral surface of the said exterior body,
The second electrode lead, the starting point of the outer second electrode current collector exposed portion, the starting point of the outer first electrode current collector exposed portion, the starting point of the both-side second electrode current collector exposed portion, and the both side first The starting point of the electrode current collector exposed portion is located on a separate radius of the winding center.

本発明によれば、セパレータの厚み方向に段差を発生し得る集電体露出部などを適切に配置することにしたため、局所的な極間距離の狭小化を抑制し、内部短絡を抑制してサイクル特性の低下を改善し得る信頼性の高い非水電解質二次電池を提供することができる。   According to the present invention, since the current collector exposed portion that can generate a step in the thickness direction of the separator is appropriately disposed, the local inter-electrode distance is suppressed and the internal short circuit is suppressed. It is possible to provide a highly reliable nonaqueous electrolyte secondary battery that can improve deterioration of cycle characteristics.

以下、本発明の非水電解質二次電池につき、図面を参照して詳細に説明する。なお、本明細書において、濃度、充填量及び配合量などについての「％」は特記しない限り質量百分率を表すものとする。   Hereinafter, the nonaqueous electrolyte secondary battery of the present invention will be described in detail with reference to the drawings. In the present specification, “%” for the concentration, filling amount, blending amount, and the like represents a mass percentage unless otherwise specified.

図１〜図３は本発明の非水電解質二次電池の一実施形態を示すもので、図１は本発明の非水電解質二次電池の一実施形態を示す縦断面図、図２は本発明の非水電解質二次電池に係る巻回電極体を示す斜視図、図３は同じく巻回電極体を横方向に切断した断面図である。
以下、正極を第１電極、負極を第２電極として説明する。 1 to 3 show one embodiment of the nonaqueous electrolyte secondary battery of the present invention, FIG. 1 is a longitudinal sectional view showing one embodiment of the nonaqueous electrolyte secondary battery of the present invention, and FIG. The perspective view which shows the winding electrode body which concerns on the nonaqueous electrolyte secondary battery of invention, FIG. 3 is sectional drawing which cut | disconnected the winding electrode body similarly in the horizontal direction.
Hereinafter, the positive electrode is described as a first electrode, and the negative electrode is described as a second electrode.

本発明の非水電解質二次電池としては、例えばリチウムイオン二次電池を挙げることができ、そのリチウムイオン二次電池の中央部を縦方向に切断して示したものが図１である。
図１に示すように、リチウムイオン二次電池１は、外装体の一例である円筒状の電池缶２と、この電池缶２内に収納される巻回電極体３と、電池内部の異常な圧力上昇や過大な充電を防止する安全弁装置４と、電池缶２の開口部を閉じる端子板５等によって構成されている。 Examples of the non-aqueous electrolyte secondary battery of the present invention include a lithium ion secondary battery, and FIG. 1 shows a center portion of the lithium ion secondary battery cut in the vertical direction.
As shown in FIG. 1, a lithium ion secondary battery 1 includes a cylindrical battery can 2 that is an example of an exterior body, a wound electrode body 3 that is housed in the battery can 2, and an abnormal condition inside the battery. It comprises a safety valve device 4 that prevents pressure rise and excessive charging, a terminal plate 5 that closes the opening of the battery can 2, and the like.

電池缶２は、鉄（Ｆｅ）などの導電性を有する金属によって中空で有底の円筒体として形成されている。この電池缶２の底部には、中央部を若干外側へ円形に膨出させた端子部２ａが設けられている。この電池缶２の内面は、例えばニッケルめっきを施したり導電性塗料を塗布するなどして、電池缶２の導電性を高める構成とすることが好ましい。
また、電池缶２の外周面は、例えばプラスチックシートや紙などによって形成される外装ラベルで覆われたり、絶縁性塗料が塗布されて保護される。 The battery can 2 is formed as a hollow, bottomed cylindrical body with a conductive metal such as iron (Fe). At the bottom of the battery can 2, there is provided a terminal portion 2a having a central portion bulged slightly outward. The inner surface of the battery can 2 is preferably configured to increase the conductivity of the battery can 2 by, for example, applying nickel plating or applying a conductive paint.
Moreover, the outer peripheral surface of the battery can 2 is covered with an exterior label formed of, for example, a plastic sheet or paper, or is protected by applying an insulating paint.

電池缶２内に収納される巻回電極体３は、図１〜図３に示すような構成を有している。即ち、巻回電極体３は、帯状に形成された正極６（第１電極）及び負極７（第２電極）と、同じく帯状に形成された２つのセパレータ８及び９とを備えている。正極６と負極７との間に一方のセパレータ８を介在させるとともに、正極６の一方のセパレータ８と反対側に他方のセパレータ９が配置される。このように４層に重ね合わされた積層体を、正極６を内側にして巻回することにより、渦巻き状に巻回された巻回電極体３が構成されている（図２参照）。   The wound electrode body 3 housed in the battery can 2 has a configuration as shown in FIGS. That is, the wound electrode body 3 includes a positive electrode 6 (first electrode) and a negative electrode 7 (second electrode) formed in a strip shape, and two separators 8 and 9 that are also formed in a strip shape. One separator 8 is interposed between the positive electrode 6 and the negative electrode 7, and the other separator 9 is disposed on the opposite side of the positive electrode 6 from the one separator 8. A wound electrode body 3 wound in a spiral shape is formed by winding the laminated body superposed on the four layers with the positive electrode 6 inside (see FIG. 2).

図２及び図３を参照して、正極６は、帯状に形成される正極集電体６ｍと、この正極集電体６ｍの両面に塗布される正極合剤層６ｉ，６ｏとから構成されている。この巻回構造において、正極合剤層６ｉは内側正極合剤層（内側第１電極合剤層）に相当し、正極合剤６ｏは外側正極合剤層（外側第１電極合剤層）に相当する。   2 and 3, the positive electrode 6 is composed of a positive electrode current collector 6m formed in a strip shape and positive electrode mixture layers 6i and 6o applied to both surfaces of the positive electrode current collector 6m. Yes. In this winding structure, the positive electrode mixture layer 6i corresponds to an inner positive electrode mixture layer (inner first electrode mixture layer), and the positive electrode mixture 6o serves as an outer positive electrode mixture layer (outer first electrode mixture layer). Equivalent to.

正極集電体６ｍとしては、例えば厚み１２μｍのアルミニウム箔を用いることができる。
この正極集電体６ｍの両面に、正極合剤スラリーを均一に塗布することによって正極合剤層６ｉ，６ｏが形成される。
この際、本実施形態の非水電解質二次電池では、正極集電体６ｍの長手方向の一端（巻回終端）方向に沿って、正極合剤スラリーをその内面、外面又は両面に適宜塗布しないようにし、それぞれ内側正極集電体露出部、外側正極集電体露出部及び両側正極集電体露出部を形成することができる。 As the positive electrode current collector 6m, for example, an aluminum foil having a thickness of 12 μm can be used.
Positive electrode mixture layers 6i and 6o are formed by uniformly applying a positive electrode mixture slurry on both surfaces of the positive electrode current collector 6m.
At this time, in the nonaqueous electrolyte secondary battery of this embodiment, the positive electrode mixture slurry is not appropriately applied to the inner surface, the outer surface, or both surfaces along the one end (winding end) direction of the positive electrode current collector 6m in the longitudinal direction. In this way, an inner positive electrode current collector exposed portion, an outer positive electrode current collector exposed portion, and a both-side positive electrode current collector exposed portion can be formed.

本実施形態においては、巻回終端の方向に沿って、（１）内側正極集電体露出部と両側正極集電体露出部とが連続する部分を有する態様、又は（２）外側正極集電体露出部と両側正極集電体露出部とが連続する部分を有する態様を採ることができる。
上記（１）又は（２）の連続部分は、正極６の巻回領域のいずれかの箇所に形成すればよいが、セパレータの局所的引き伸ばしを効果的に改善する観点からは、巻回終端の直前に形成することが好ましい。
このような連続部分については、便宜上、後の実施例で詳しく説明することにし、図３においては、両側正極集電体露出部６ｂのみを図示した。 In the present embodiment, along the direction of the winding end, (1) an aspect having a portion in which the inner positive electrode current collector exposed portion and both side positive electrode current collector exposed portions are continuous, or (2) outer positive current collector. A mode in which the body exposed portion and the both-side positive electrode current collector exposed portion have a continuous portion can be taken.
The continuous part (1) or (2) may be formed in any part of the winding region of the positive electrode 6, but from the viewpoint of effectively improving the local stretching of the separator, It is preferable to form it immediately before.
For convenience, such a continuous portion will be described in detail in a later embodiment. In FIG. 3, only the both-side positive electrode collector exposed portion 6b is shown.

正極合剤の正極活物質としては、次のようなものを用いることができる。例えば、アルカリ金属を含有する遷移金属とのカルコゲン化合物、特に、アルカリ金属と遷移金属との酸化物を用いることができる。
また、結晶構造の見地からは、層状化合物やスピネル型化合物がよく用いられ、層状化合物としては、次の一般式ＬｉＭＯ２
（式中のＭは鉄（Ｆｅ）、コバルト（Ｃｏ）、ニッケル（Ｎｉ）、マンガン（Ｍｎ）、銅（Ｃｕ）、亜鉛（Ｚｎ）、アルミニウム（Ａｌ）、スズ（Ｓｎ）、ホウ素（Ｂ）、ガリウム（Ｇａ）、クロム（Ｃｒ）、バナジウム（Ｖ）、チタン（Ｔｉ）、マグネシウム（Ｍｇ）、カルシウム（Ｃａ）、ストロンチウム（Ｓｒ）又はこれらの任意の混合物を示す）で表されるものを好適に用いることができる。 The following can be used as the positive electrode active material of the positive electrode mixture. For example, a chalcogen compound with a transition metal containing an alkali metal, particularly an oxide of an alkali metal and a transition metal can be used.
From the viewpoint of the crystal structure, layered compounds and spinel compounds are often used. As the layered compounds, the following general formula LiMO 2 is used.
(M in the formula is iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn), copper (Cu), zinc (Zn), aluminum (Al), tin (Sn), boron (B) , Gallium (Ga), chromium (Cr), vanadium (V), titanium (Ti), magnesium (Mg), calcium (Ca), strontium (Sr) or any mixture thereof) It can be used suitably.

上述の巻回電極体３の作製に際しては、このような正極活物質を用いて正極合剤スラリーを作製する。この正極合剤スラリーは、例えば粉末ＬｉＣｏＯ２を８６％、導電剤としてグラファイトを１０％、結着剤としてポリフッ化ビニリデン４％を混合して正極合剤を調製し、これをＮ−メチル−２−ピロリドンに分散させることによって作製することができる。 In producing the above-described wound electrode body 3, a positive electrode mixture slurry is produced using such a positive electrode active material. This positive electrode mixture slurry is prepared by mixing, for example, 86% of powdered LiCoO 2 , 10% of graphite as a conductive agent, and 4% of polyvinylidene fluoride as a binder to prepare a positive electrode mixture. -It can be prepared by dispersing in pyrrolidone.

この正極合剤スラリーを正極集電体６ｍのほぼ両面に、望ましくは電極巻き終り部（巻回方向の終端）近傍において、上述した内側正極集電体露出部又は外側正極集電体露出部、及び両側正極集電体露出部が形成されるようにして均一に塗布する。
なお、両側正極集電体露出部６ｂは、巻回電極体３の外径（外周面の直径）をｄとするときに、π（円周率）×ｄ以上、即ち一周回以上の長さとなるようにする。
このように正極合剤スラリーを正極集電体６ｍのほぼ両面に塗布した後、両面の正極合剤スラリーを乾燥させる。その後、ローラプレス機にかけて圧縮成形を行うことにより、帯状をなす正極６が形成される。 The positive electrode mixture slurry is disposed on almost both surfaces of the positive electrode current collector 6m, preferably in the vicinity of the electrode winding end portion (end in the winding direction), and the above-described inner positive electrode current collector exposed portion or outer positive electrode current collector exposed portion, And it apply | coats uniformly so that a positive electrode collector exposed part on both sides may be formed.
The both-side positive electrode current collector exposed portion 6b has a length of π (circumferential ratio) × d or more, that is, a length of one or more turns when the outer diameter (diameter of the outer peripheral surface) of the wound electrode body 3 is d. To be.
Thus, after apply | coating the positive mix slurry on almost both surfaces of the positive electrode collector 6m, the positive mix slurry of both surfaces is dried. Then, the positive electrode 6 which makes a strip | belt shape is formed by performing compression molding on a roller press machine.

一方、負極７は、同じく帯状に形成された負極集電体７ｍと、この負極集電体７ｍの両面、即ち内面又は外面に被覆された内側負極合剤層７ｉ、外側負極合剤層７ｏとから構成されている。負極集電体７ｍとしては、例えば、厚み１２μｍの銅箔を用いることができる。
この負極集電体７ｍのほぼ両面に、負極合剤スラリーを均一に塗布することによって内側負極合剤層７ｉ、７ｏが形成される。この際、正極と同様に、負極集電体７ｍの長手方向の一端（巻回終端）方向に沿って、正極合剤スラリーをその内面、外面又は両面に適宜塗布しないようにし、それぞれ内側負極集電体露出部、外側負極集電体露出部及び両側正極集電体露出部を形成することができる。 On the other hand, the negative electrode 7 includes a negative electrode current collector 7m that is also formed in a strip shape, and an inner negative electrode mixture layer 7i and an outer negative electrode mixture layer 7o that are coated on both surfaces of the negative electrode current collector 7m, that is, the inner surface or the outer surface. It is composed of As the negative electrode current collector 7m, for example, a copper foil having a thickness of 12 μm can be used.
Inner negative electrode mixture layers 7i and 7o are formed by uniformly applying the negative electrode mixture slurry on almost both surfaces of the negative electrode current collector 7m. At this time, similarly to the positive electrode, the positive electrode mixture slurry is not appropriately applied to the inner surface, outer surface, or both surfaces along the one end (winding end) direction of the negative electrode current collector 7m in the longitudinal direction. An electric body exposed portion, an outer negative electrode current collector exposed portion, and both side positive electrode current collector exposed portions can be formed.

本実施形態においては、巻回終端の方向に沿って、外側負極集電体露出部と両側負極集電体露出部とが連続する部分を有する態様を採ることが好ましい。
上記の連続部分は、負極７の巻回領域のいずれかの箇所に形成すればよいが、セパレータの局所的引き伸ばしを効果的に改善する観点からは、巻回終端の直前に形成することが好ましい。
このような連続部分については、便宜上、後の実施例で詳しく説明することにし、図３においては、両側負極集電体露出部７ｂのみを図示した。 In this embodiment, it is preferable to take the aspect which has the part which an outer side negative electrode collector exposed part and a both-sides negative electrode collector exposed part continue along the direction of a winding termination | terminus.
The continuous portion may be formed in any part of the winding region of the negative electrode 7, but it is preferably formed immediately before the winding end from the viewpoint of effectively improving the local stretching of the separator. .
For convenience, such a continuous portion will be described in detail in a later embodiment. In FIG. 3, only the both-side negative electrode current collector exposed portion 7b is shown.

なお、本実施形態の非水電解質二次電池においては、外側負極集電体露出部と内側正極集電体露出部との寸法差を、２ｍｍ以上にすることが好ましい。   In the nonaqueous electrolyte secondary battery of this embodiment, it is preferable that the dimensional difference between the outer negative electrode current collector exposed portion and the inner positive electrode current collector exposed portion is 2 mm or more.

負極合剤の負極活物質としては、例えばリチウムをドープ（吸蔵）し且つ脱ドープ（離脱）し得る合金、化合化可能な材料、炭素質材料又はこれらの任意の組合せに係るものを用いることができる。
このリチウムを吸蔵・離脱可能な負極材料としては、例えばリチウムと合金若しくは化合物を形成可能な金属若しくは半導体、又はこれらの合金若しくは化合物を挙げることができる。 As the negative electrode active material of the negative electrode mixture, for example, an alloy that can be doped (occluded) with lithium and can be dedoped (released), a compoundable material, a carbonaceous material, or any combination thereof can be used. it can.
Examples of the negative electrode material capable of inserting and extracting lithium include a metal or semiconductor capable of forming an alloy or compound with lithium, or an alloy or compound thereof.

これら金属、合金又は化合物は、例えば、次の化学式ＤｓＥｔＬｉｕ
（式中のＤはリチウムと合金又は化合物を形成可能な金属元素及び半導体元素のうちの少なくとも１種、Ｅはリチウム及びＤ以外の金属元素及び半導体元素のうちの少なくとも１種を示し、Ｓ、ｔ及びｕはそれぞれｓ＞０、ｔ≧０、ｕ≧０を満足する）で表される。 These metals, alloys or compounds are represented, for example, by the following chemical formula D s E t Li u
(In the formula, D represents at least one of a metal element and a semiconductor element capable of forming an alloy or compound with lithium, E represents at least one of a metal element and a semiconductor element other than lithium and D, and S, t and u satisfy s> 0, t ≧ 0, and u ≧ 0, respectively).

上記化学式において、リチウムと合金又は化合物を形成可能な金属元素、半導体元素（Ｄ）としては、４Ｂ族の金属元素又は半導体元素が好ましく、特に好ましいのはケイ素又はスズであり、最も好ましいのはケイ素である。
更に、これらの合金又は化合物も好適であり、具体的には、ＳｉＢ４、ＳｉＢ６、Ｍｇ２Ｓｉ、Ｍｇ２Ｓｎ、Ｎｉ２Ｓｉ、ＴｉＳｉ２、ＭｏＳｉ２、ＣｏＳｉ２、ＮｉＳｉ２、ＣａＳｉ２、ＣｒＳｉ２、Ｃｕ５Ｓｉ、ＦｅＳｉ２、ＭｎＳｉ２、ＮｂＳｉ２、ＴａＳｉ２、ＶＳｉ２、ＷＳｉ２及びＺｎＳｉ２等を挙げることができる。 In the above chemical formula, the metal element or semiconductor element (D) capable of forming an alloy or compound with lithium is preferably a group 4B metal element or semiconductor element, particularly preferably silicon or tin, and most preferably silicon. It is.
Furthermore, these alloys or compounds are also suitable, specifically, SiB 4 , SiB 6 , Mg 2 Si, Mg 2 Sn, Ni 2 Si, TiSi 2 , MoSi 2 , CoSi 2 , NiSi 2 , CaSi 2 , CrSi 2, Cu 5 Si, may be mentioned FeSi 2, MnSi 2, NbSi 2 , TaSi 2, VSi 2, WSi 2 and ZnSi 2, or the like.

また、リチウムを吸蔵・離脱可能な負極材料の他の例としては、炭素材料、金属酸化物及び高分子材料などを挙げることができる。
炭素材料としては、例えば、難黒鉛化性炭素、人造黒鉛、コークス類、グラファイト類、ガラス状炭素類、有機高分子化合物焼成体、炭素繊維、活性炭及びカーボンブラック類などを例示できる。このうち、コークス類には、ピッチコークス、ニードルコークス及び石油コークス等がある。また、有機高分子化合物焼成体は、フェノール類やフラン類等の高分子材料を適当な温度で焼成して炭素化したものである。更に、金属酸化物としては、酸化鉄、酸化ルテニウム、酸化モリブデン及び酸化スズ等がある。また、高分子材料としては、ポリアセチレンやポリピロール等を挙げることができる。 Other examples of the negative electrode material capable of inserting and extracting lithium include carbon materials, metal oxides, and polymer materials.
Examples of the carbon material include non-graphitizable carbon, artificial graphite, cokes, graphites, glassy carbons, organic polymer compound fired bodies, carbon fibers, activated carbon, and carbon blacks. Among these, coke includes pitch coke, needle coke, petroleum coke, and the like. The organic polymer compound fired body is obtained by firing and polymerizing a polymer material such as phenols and furans at an appropriate temperature. Furthermore, examples of the metal oxide include iron oxide, ruthenium oxide, molybdenum oxide, and tin oxide. Examples of the polymer material include polyacetylene and polypyrrole.

なお、本発明では、充放電時における負極合剤層の膨張収縮が適切に抑制されるので、そのような膨張収縮率の比較的大きな負極合剤、例えば非炭素材料系の材料を使用する際に有効である。   In the present invention, since the expansion and contraction of the negative electrode mixture layer during charge / discharge is appropriately suppressed, when using such a negative electrode mixture having a relatively large expansion / contraction rate, such as a non-carbon material. It is effective for.

次に、非水電解質組成物としては、非水溶媒、固体電解質、高分子電解質や高分子化合物に電解質塩を混合又は溶解させた液体状、固体状又はゲル状電解質などを用いることができる。
ここで、非水溶媒としては、例えば、エチレンカーボネート、プロピレンカーボネート、γ−バレロラクトン、ビニレンカーボネート等の環状エステル化合物や、ジエトキシエタン、テトラヒドロフラン、２−メチルテトラヒドロフラン、１，３−ジオキサン等のエーテル化合物や、酢酸メチル、プロピレン酸メチル等の鎖状エステル化合物や、ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネート等の鎖状カーボネート、２，４−ジフルオロアニソール、２，６−ジフルオロアニソール、４−プロモベラトロール等を挙げることができ、これらを単独溶媒又は２種類以上の混合溶媒として使用することができる。 Next, as the nonaqueous electrolyte composition, a nonaqueous solvent, a solid electrolyte, a liquid electrolyte, a solid electrolyte, or a gel electrolyte in which an electrolyte salt is mixed or dissolved in a polymer electrolyte or a polymer compound can be used.
Here, examples of the non-aqueous solvent include cyclic ester compounds such as ethylene carbonate, propylene carbonate, γ-valerolactone, and vinylene carbonate, and ethers such as diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, and 1,3-dioxane. Compounds, chain ester compounds such as methyl acetate and methyl propylene acid, chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, 2,4-difluoroanisole, 2,6-difluoroanisole, 4-promobella A trol etc. can be mentioned, These can be used as a single solvent or 2 or more types of mixed solvents.

また、ゲル状電解質に用いられる高分子材料としては、例えば、ポリアクリロニトリルとポリアクリロニトリルの共重合体を使用することができる。
共重合モノマー（ビニル系モノマー）としては、例えば、酢酸ビニル、メタクリル酸メチル、メタクリル酸ブチル、アクリル酸メチル、アクリル酸ブチル、イタコン酸、水素化メチルアクリレート、水素化エチルアクリレート、アクリルアミド、塩化ビニル、フッ化ビニリデン、塩化ビニリデン、フッ化ビニリデン−ヘキサフルオロプロピレンの共重合体、ポリ四フッ化エチレン等を挙げることができる。
更に、アクリロニトリルブタジエンゴム、アクリロニトリルブタジエンスチレン樹脂、アクリロニトリル塩化ポリエチレンプロピレンジエンスチレン樹脂、アクリロニトリル塩化ビニル樹脂、アクリロニトリルメタアクリレート樹脂、アクリロニトリルアクリレート樹脂等を使用することができる。 Moreover, as a polymer material used for the gel electrolyte, for example, a copolymer of polyacrylonitrile and polyacrylonitrile can be used.
Examples of the copolymerizable monomer (vinyl monomer) include vinyl acetate, methyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, itaconic acid, hydrogenated methyl acrylate, hydrogenated ethyl acrylate, acrylamide, vinyl chloride, Examples thereof include vinylidene fluoride, vinylidene chloride, a vinylidene fluoride-hexafluoropropylene copolymer, and polytetrafluoroethylene.
Further, acrylonitrile butadiene rubber, acrylonitrile butadiene styrene resin, acrylonitrile chlorinated polyethylene propylene diene styrene resin, acrylonitrile vinyl chloride resin, acrylonitrile methacrylate resin, acrylonitrile acrylate resin and the like can be used.

更に、ゲル状電解質に用いられる高分子材料としては、ポリフッ化ビニリデンとポリフッ化ビニリデンの共重合体を使用することができる。
そして、共重合モノマーとしては、例えば、ヘキサフルオロプロピレンやテトラフルオロエチレン等を挙げることができる。なお、ゲル状電解質に用いられる高分子材料としては、これらを単独で又は２種以上混合して使用することができる。 Furthermore, as a polymer material used for the gel electrolyte, a copolymer of polyvinylidene fluoride and polyvinylidene fluoride can be used.
And as a copolymerization monomer, hexafluoropropylene, tetrafluoroethylene, etc. can be mentioned, for example. In addition, as a polymeric material used for gel electrolyte, these can be used individually or in mixture of 2 or more types.

ゲル状電解質層を形成するには、非水溶媒として、例えば、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ビニレンカーボネート、γ−ブチルラクトン、γ−バレロラクトン等の環状エステル化合物や、ジエトキシエタン、テトラヒドロフラン、２−メチルテトラヒドロフラン、１，３−ジオキサン等のエーテル化合物や、酢酸メチル、プロピレン酸メチル等の鎖状エステル化合物や、ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネート等の鎖状カーボネート、２，４−ジフルオロアニソール、２，６−ジフルオロアニソール、４−プロモベラトロール等を単独溶媒又は２種類以上の混合溶媒として使用することができる。   In order to form the gel electrolyte layer, as the nonaqueous solvent, for example, cyclic ester compounds such as ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, γ-butyllactone, γ-valerolactone, diethoxyethane, tetrahydrofuran Ether compounds such as 2-methyltetrahydrofuran and 1,3-dioxane, chain ester compounds such as methyl acetate and methyl propylene acid, chain carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, 2,4- Difluoroanisole, 2,6-difluoroanisole, 4-promoveratrol and the like can be used as a single solvent or a mixed solvent of two or more kinds.

更に、ゲル状電解質層は、ゲル状電解質としてポリフッ化ビニリデンを使用する場合には、ポリヘキサフルオロプロピレン、ポリ四フッ化エチレン等が共重合された多元系高分子から成るゲル状電解質を用いて形成されていることが好ましい。これにより、より機械的強度の高いゲル状電解質を得ることができる。   Furthermore, the gel electrolyte layer uses a gel electrolyte composed of a multi-component polymer in which polyhexafluoropropylene, polytetrafluoroethylene, or the like is copolymerized when polyvinylidene fluoride is used as the gel electrolyte. Preferably it is formed. As a result, a gel electrolyte having higher mechanical strength can be obtained.

また、電解質塩としては、例えば、ＬｉＰＦ６、ＬｉＡｓＦ６、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＣＦ３ＳＯ３、ＬｉＮ（ＣｎＦ２ｎ＋１ＳＯ２）２、ＬｉＣ４Ｆ９ＳＯ３等のリチウム塩を単独で又は２種類以上混合して使用することができる。 Examples of the electrolyte salt include lithium salts such as LiPF 6 , LiAsF 6 , LiBF 4 , LiClO 4 , LiCF 3 SO 3 , LiN (CnF 2n + 1 SO 2 ) 2 , LiC 4 F 9 SO 3 singly or 2 A mixture of more than one type can be used.

巻回電極体の作製に際しては、このような負極活物質を用いて負極合剤スラリーを作製する。この負極合剤スラリーは、例えば、黒鉛材料粉末を９０％、結着剤としてポリフッ化ビニリデンを１０％の割合で混合して負極合剤を調製し、これをＮ−メチル−２−ピロリドンに分散させることによって作製することができる。
この負極合剤スラリーを負極集電体７ｍの両面に、外側負極集電体露出部及び両側負極集電体露出部が形成されるようにして均一に塗布する。 When producing a wound electrode body, a negative electrode mixture slurry is produced using such a negative electrode active material. This negative electrode mixture slurry is prepared, for example, by mixing 90% of graphite material powder and 10% of polyvinylidene fluoride as a binder to prepare a negative electrode mixture, which is dispersed in N-methyl-2-pyrrolidone Can be produced.
The negative electrode mixture slurry is uniformly applied to both surfaces of the negative electrode current collector 7m so that the outer negative electrode current collector exposed portion and the both side negative electrode current collector exposed portions are formed.

ここで、両側負極集電体露出部７ｂは、巻回電極体３の外径をｄとするときに、π×ｄ以上、即ち一周回以上の長さとなるようにすることが好ましい。
このように負極合剤スラリーを負極集電体７ａの両面に塗布した後、両面の正極合剤スラリーを乾燥させる。その後、ローラプレス機にかけて圧縮成形を行うことにより、帯状をなす負極７が形成される。 Here, it is preferable that the negative electrode collector exposed portions 7b on both sides have a length of π × d or more, that is, a length of one turn or more when the outer diameter of the wound electrode body 3 is d.
Thus, after apply | coating the negative mix slurry on both surfaces of the negative electrode collector 7a, the positive mix slurry of both surfaces is dried. Then, the negative electrode 7 which makes a strip | belt shape is formed by performing compression molding on a roller press machine.

また、セパレータ８，９としては、例えば、微多孔性のポリプロピレンフィルムを用いることができる。このセパレータ８，９の厚さは２５μｍ程度であり、これらを正極６と負極７との間に介在させる。そして、負極７、セパレータ８、正極６及びセパレータ９の順に積層し、正極６を巻回中心に関して内側になるように配置しつつ、これを一端から他端まで巻回させる。そして、粘着テープ等を使用して巻回方向の外周側端部（巻回終端）を固定する。これにより、渦巻き状に巻回してなる巻回電極体３が作製される。   As the separators 8 and 9, for example, a microporous polypropylene film can be used. The separators 8 and 9 have a thickness of about 25 μm and are interposed between the positive electrode 6 and the negative electrode 7. Then, the negative electrode 7, the separator 8, the positive electrode 6, and the separator 9 are laminated in this order, and the positive electrode 6 is wound from one end to the other end while being disposed inside the winding center. Then, the outer peripheral side end (winding end) in the winding direction is fixed using an adhesive tape or the like. Thereby, the wound electrode body 3 wound in a spiral shape is produced.

このような構成を有する巻回電極体３には、図１に示すように、正極集電体６ｍに接続された正極リード１２と、負極集電体７ｍに接続された負極リード１３とが設けられている。そして、正極リード１２は、巻回電極体３の軸方向の一端である上面側に導出され、また、負極リード１３は、軸方向の他端である下面側に導出されている。
更に、巻回電極体３の中央部の穴には、パイプ状に形成されたセンタピン１４が挿入されている。また、巻回電極体３の上面には上絶縁体１５が配置され、下面には下絶縁体１６が配置されている。 As shown in FIG. 1, the wound electrode body 3 having such a configuration is provided with a positive electrode lead 12 connected to the positive electrode current collector 6m and a negative electrode lead 13 connected to the negative electrode current collector 7m. It has been. The positive electrode lead 12 is led out to the upper surface side that is one end of the spirally wound electrode body 3 in the axial direction, and the negative electrode lead 13 is led out to the lower surface side that is the other end in the axial direction.
Further, a center pin 14 formed in a pipe shape is inserted into the hole at the center of the wound electrode body 3. An upper insulator 15 is disposed on the upper surface of the wound electrode body 3, and a lower insulator 16 is disposed on the lower surface.

センタピン１４は、電池内部の圧力異常時に、巻回電極体３の潰れを防止又は抑制して内部ショートの発生を防止すると共に、電池缶２の底部に溜まったガスを上部の安全弁装置４側に移動させることを主目的とするものである。
更に、巻回電極体３の電極密度を高めるため、センタピン１４の材質としては、軽くて強度の大きいもの、例えば、ステンレス鋼（例えば、ＳＵＳ３０４やＳＵＳ４３０）、ニッケル鋼、金属チタンが好適であるが、これに限定されるものではない。
センタピン１４の構成材としてＳＵＳ３０４を用いる場合には、センタピン１４の外径をできるだけ小さくしながら、中央穴の内径をできるだけ大きくすると、この中央穴を通過するガスの流量を大きく確保することができる。 The center pin 14 prevents or suppresses the occurrence of an internal short circuit by preventing or suppressing the collapse of the wound electrode body 3 when the internal pressure of the battery is abnormal, and causes the gas accumulated at the bottom of the battery can 2 to flow to the upper safety valve device 4 side. The main purpose is to move it.
Furthermore, in order to increase the electrode density of the wound electrode body 3, the material of the center pin 14 is preferably light and strong, for example, stainless steel (for example, SUS304 or SUS430), nickel steel, or titanium metal. However, the present invention is not limited to this.
When SUS304 is used as the constituent material of the center pin 14, if the inner diameter of the center hole is made as large as possible while making the outer diameter of the center pin 14 as small as possible, a large flow rate of gas passing through the center hole can be secured.

このような関係とすることにより、巻回電極体３が温度上昇により膨張して外径が大きくなったときにも、電池缶２の内面に作用する圧力を最小にし、内部圧力の上昇を最小限に押さえることができる。そして、センタピン１４の外径をできるだけ小さくすることと相俟って正極６及び負極７の各合剤層の長さをできるだけ長くすることができる。従って、合剤層を可及的に長くして巻回電極体３全体の容量を増加させることができる。   With this relationship, even when the wound electrode body 3 expands due to a temperature rise and the outer diameter increases, the pressure acting on the inner surface of the battery can 2 is minimized, and the increase in internal pressure is minimized. It can be held to the limit. Then, in combination with making the outer diameter of the center pin 14 as small as possible, the length of each mixture layer of the positive electrode 6 and the negative electrode 7 can be made as long as possible. Therefore, it is possible to increase the capacity of the entire wound electrode body 3 by making the mixture layer as long as possible.

また、上下の絶縁体１５，１６は、その外径が巻回電極体３の外径よりも若干小径とされており、それぞれの中央部には表裏面を貫通するセンタ穴１５ａ，１６ａが設けられている。そして、上絶縁体１５には正極リード１２が貫通されていて、負極リード２３は下絶縁体１６の外側を通して下面に集められている。
このような巻回電極体３が上下の絶縁体１５，１６と共に電池缶２の内部に収納されている。そして、下絶縁板１６の下方に集められた負極リード１３が、一まとめにされて端子部２ａの内面に溶接等の固着手段により固定されて電気的に接続されている。 The upper and lower insulators 15 and 16 have an outer diameter slightly smaller than the outer diameter of the wound electrode body 3, and center holes 15 a and 16 a penetrating the front and rear surfaces are provided in the respective central portions. It has been. The upper insulator 15 penetrates the positive electrode lead 12, and the negative electrode lead 23 is collected on the lower surface through the outside of the lower insulator 16.
Such a wound electrode body 3 is housed inside the battery can 2 together with the upper and lower insulators 15 and 16. The negative leads 13 collected below the lower insulating plate 16 are bundled together and fixed to the inner surface of the terminal portion 2a by fixing means such as welding and electrically connected.

この電池缶２内において、下絶縁板１６の下方領域は、下絶縁板１６のセンタ穴１６ａ、センタピン１４の中央穴１４ａ及び上絶縁板１５のセンタ穴１５ａを介して上絶縁板１５の上方領域と連通されている。上絶縁板１５の上方領域である電池缶２の開口部には、安全弁装置４と端子板５とが互いに重ね合わされて装着されている。
安全弁装置４及び端子板５は共に円板状に形成されており、その外周縁がリング状をなすガスケット１７によって保持され、これらにより電池缶２の開口部が閉じられている。そして、ガスケット１７を介して電池缶２の開口部近傍をカシメ、又はレーザ溶接を施すことにより、電池缶２の開口部が液密に封口されている。 In the battery can 2, the lower region of the lower insulating plate 16 is an upper region of the upper insulating plate 15 via the center hole 16 a of the lower insulating plate 16, the center hole 14 a of the center pin 14, and the center hole 15 a of the upper insulating plate 15. Communicated with. A safety valve device 4 and a terminal plate 5 are attached to each other in an opening of the battery can 2 that is an upper region of the upper insulating plate 15.
Both the safety valve device 4 and the terminal plate 5 are formed in a disc shape, and the outer peripheral edge thereof is held by a ring-shaped gasket 17, thereby closing the opening of the battery can 2. And the opening part of the battery can 2 is liquid-tightly sealed by caulking or laser welding the vicinity of the opening part of the battery can 2 via the gasket 17.

安全弁装置４は、電池内部でガスが異常発生した時に電池内部のガスを外部へ逃がす機能を有する開裂弁１８と、過大な充電時に電流を遮断する機能を有する遮断弁１９とから構成されている。
開裂弁１８は、所定以上の圧力が加えられたときに破断される開裂部を有し、この開裂部が所定以上の圧力で破断されることにより、電池内部のガスを外部へ逃がすようにしている。また、遮断弁１９は、過大な電流が流れたときに、その電流回路を遮断して電流が流れないようにするもので、例えば、ＰＴＣ素子等を適用することができる。 The safety valve device 4 includes a cleavage valve 18 having a function of letting the gas inside the battery escape to the outside when a gas abnormality occurs inside the battery, and a shut-off valve 19 having a function of cutting off the current during excessive charging. .
The cleavage valve 18 has a cleavage portion that is broken when a predetermined pressure or higher is applied, and the cleavage portion is broken at a pressure higher than the predetermined pressure so that the gas inside the battery is released to the outside. Yes. The shut-off valve 19 shuts off the current circuit so that no current flows when an excessive current flows. For example, a PTC element or the like can be applied.

この安全弁装置４の遮断弁１９に対して、上絶縁体１５の上方に導出された多数の正極リード１２が一まとめにされて溶接等の固着手段により固定されて電気的に接続されている。遮断弁１９の半径方向内側は、円形とされて下方へ膨出されている。これに対応するよう端子板５の半径方向内側は、同じ円形ではあるが、遮断弁１９とは反対の上方へ膨出されている。この端子板５には、電池内部の異常なガスを外部へ逃がすためのガス抜き穴５ａが設けられている。   A large number of positive leads 12 led out above the upper insulator 15 are gathered together and fixed and electrically connected to a shutoff valve 19 of the safety valve device 4 by fixing means such as welding. The radially inner side of the shut-off valve 19 is circular and bulges downward. To correspond to this, the inner side in the radial direction of the terminal plate 5 is the same circular shape, but is bulged upward opposite to the shutoff valve 19. The terminal plate 5 is provided with a gas vent hole 5a for allowing abnormal gas inside the battery to escape to the outside.

このような構成を有するリチウムイオン二次電池１は、例えば、次のようにして簡単に製造することができる。まず、上述したようにして作製した正極６及び負極７を、セパレータ８，９を介して、負極７、セパレータ８、正極６及びセパレータ９の順に積層した後、これを所定回数巻回し、巻き終り部を粘着テープで固定する。これにより、渦巻き状に巻回してなる巻回電極体３が構成される。   The lithium ion secondary battery 1 having such a configuration can be easily manufactured as follows, for example. First, the positive electrode 6 and the negative electrode 7 produced as described above are laminated in order of the negative electrode 7, the separator 8, the positive electrode 6, and the separator 9 with the separators 8 and 9 interposed therebetween. Secure the part with adhesive tape. Thereby, the winding electrode body 3 wound in a spiral shape is configured.

この巻回電極体３の中央の穴にセンタピン１４を挿入すると共にその上下に絶縁体１５，１６を配置して、これを電池缶２の穴内に収納する。次に、多数の負極リード１３を電池缶２の端子部２ａの内面に溶接し、正極リード１２を安全弁装置４に溶接する。
次に、電解液を電池缶２内に注入する。この電解液は、例えば、エチレンカーボネートとメチルエチルカーボネートを５：５なる容量比で混合した有機溶媒中に、電解質塩ＬｉＰＦ６を１モル／リットルの濃度で溶解することによって調製することができる。 The center pin 14 is inserted into the center hole of the wound electrode body 3 and the insulators 15 and 16 are disposed above and below the center pin 14 and accommodated in the hole of the battery can 2. Next, a number of negative electrode leads 13 are welded to the inner surface of the terminal portion 2 a of the battery can 2, and the positive electrode lead 12 is welded to the safety valve device 4.
Next, the electrolytic solution is injected into the battery can 2. This electrolytic solution can be prepared, for example, by dissolving the electrolyte salt LiPF 6 at a concentration of 1 mol / liter in an organic solvent in which ethylene carbonate and methyl ethyl carbonate are mixed at a volume ratio of 5: 5.

その後、アスファルトで表面を塗布した封口用のガスケット１７に安全弁装置４及び端子板５を装着し、これらで電池缶２の開口部を閉鎖する。
次に、電池缶２の開口部をカシメることにより、ガスケット１７を介して安全弁装置４と端子板５を固定する。これにより、外径が円筒形をなすリチウムイオン二次電池１を製造することができる。 Thereafter, the safety valve device 4 and the terminal plate 5 are attached to the sealing gasket 17 whose surface is coated with asphalt, and the opening of the battery can 2 is closed with these.
Next, the safety valve device 4 and the terminal plate 5 are fixed via the gasket 17 by crimping the opening of the battery can 2. Thereby, the lithium ion secondary battery 1 whose outer diameter makes a cylindrical shape can be manufactured.

以下、本発明を実施例及び比較例により更に詳細に説明するが、本発明はこれら実施例に限定されるものではない。   EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

（実施例１〜３）
上述した電極作製方法によって電極素子最外周部における正負極形状が異なるものを作製し、所定の電極群作製方法によって構成し、所定の組立方法によって非水電解液を注液・封口することで、図４に示す各例の非水電解質二次電池を作製した。これらの実施例の電池において、正負極板形状、即ち片面側及び両面側正極集電体露出部、片面側及び両面側負極集電体露出部について、以下に詳述する。
なお、これらの電池のサイズは、ＪＩＳ Ｃ８７１１に記載されているＩＣＲ１８６５０で、電池容量は２５００ｍＡｈである。 (Examples 1-3)
By making the positive and negative electrode shape different in the electrode element outermost peripheral portion by the electrode preparation method described above, constituted by a predetermined electrode group production method, by injecting and sealing a non-aqueous electrolyte by a predetermined assembly method, The nonaqueous electrolyte secondary battery of each example shown in FIG. 4 was produced. In the batteries of these examples, the positive and negative electrode plate shapes, that is, the single-sided and double-sided positive electrode current collector exposed portions, the single-sided and double-sided negative electrode current collector exposed portions will be described in detail below.
The size of these batteries is ICR18650 described in JIS C8711, and the battery capacity is 2500 mAh.

図４は、実施例１〜３の非水電解質二次電池の概略的な横断面を示す模式的横断面図であり、巻回電極体の巻回終端近傍を示しているが、セパレータは図示していない。
同図において、この非水電解質二次電池の巻回電極体３０は、円筒状の電池缶２に収容されており、負極７、セパレータ、正極６及びセパレータの順に積層した積層体を、正極６が巻回中心３Ｃに対して内側に位置するように巻回して形成されている。 FIG. 4 is a schematic cross-sectional view showing a schematic cross-section of the nonaqueous electrolyte secondary battery of Examples 1 to 3, showing the vicinity of the winding end of the wound electrode body, but the separator is not shown in FIG. Not shown.
In this figure, a wound electrode body 30 of this non-aqueous electrolyte secondary battery is accommodated in a cylindrical battery can 2, and a laminate in which an anode 7, a separator, a cathode 6, and a separator are laminated in this order is added to the cathode 6. Is wound so as to be located on the inner side with respect to the winding center 3C.

この巻回電極体３０において、正極６は、巻回終端の方向に沿って、延在した内側正極集電体露出部６ｉｂと延在した両側正極集電体露出部６ｂとがこの順で連続した領域を有し、それぞれの始点は符号６ｉｂ（ｓ）と６ｂ（ｓ）で表されている
一方、負極７は、巻回終端の方向に沿って、延在した外側負極集電体露出部７ｏｂと延在した両側負極集電体露出部７ｂとがこの順で連続した領域を有し、それぞれの始点は符号７ｏｂ（ｓ）と７ｂ（ｓ）で表されている。
また、負極集電体７ｍの終端部近傍は、電池缶２と接合している負極リード１３と電池接続されており、負極リードの始点は符号１３（ｓ）で表されている。 In the wound electrode body 30, the positive electrode 6 has an inner positive electrode current collector exposed portion 6 ib and an extended positive electrode current collector exposed portion 6 b extending in this order along the direction of the winding end. The start points of the negative electrode 7 are indicated by reference numerals 6ib (s) and 6b (s), respectively, while the negative electrode 7 is an exposed portion of the outer negative electrode collector that extends along the direction of the winding end. 7ob and the both-side negative electrode collector exposed portion 7b extending have a continuous region in this order, and the respective starting points are denoted by reference numerals 7ob (s) and 7b (s).
Further, the vicinity of the terminal portion of the negative electrode current collector 7m is connected to the negative electrode lead 13 joined to the battery can 2, and the starting point of the negative electrode lead is represented by reference numeral 13 (s).

図４に示すように、この巻回電極体３０では、上述の内側正極集電体露出部の始点６ｉｂ（ｓ）、両側正極集電体露出部の始点６ｂ（ｓ）、外側負極集電体露出部の始点７ｏｂ（ｓ）、両側負極集電体露出部の始点７ｂ（ｓ）、及び負極リードの始点１３（ｓ）が、巻回中心３Ｃを中心とするそれぞれ別個の半径上に位置している。
よって、このような巻回電極体において、セパレータなどの厚み方向（上記の半径方向）に段差を生ずる上記各始点は、図４に示す巻回電極体では分散配置されていることになる。
特に、セパレータを介し対向して巻回延在する（併走する）正極６と負極７とにおいて、上記の始点同士が隣接し、双方の始点による段差が加算され、より大きな段差を生ずることが確実に回避されている。 As shown in FIG. 4, in this wound electrode body 30, the above-described start point 6 ib (s) of the inner positive electrode current collector exposed portion, the start point 6 b (s) of both side positive electrode current collector exposed portions, the outer negative electrode current collector The start point 7ob (s) of the exposed portion, the start point 7b (s) of the negative electrode current collector exposed portion, and the start point 13 (s) of the negative electrode lead are located on different radii centering on the winding center 3C. ing.
Therefore, in such a wound electrode body, the respective starting points that cause a step in the thickness direction (the above radial direction) of the separator or the like are dispersedly arranged in the wound electrode body shown in FIG.
In particular, in the positive electrode 6 and the negative electrode 7 that are wound while facing each other via a separator, the above-mentioned starting points are adjacent to each other, and it is certain that a step due to both the starting points is added, resulting in a larger step. Has been avoided.

このように、図４に示す巻回電極体を有する非水電解質二次電池においては、充電の際に電極合剤層が膨張して厚みが増大しても、セパレータの局所的引き伸ばしが極めて発生し難く、正−負極間の局所的狭小化も発生し難い。よって、充放電に伴うメタルの集中的析出などよる内部短絡も効果的に防止される。また、この効果は薄肉化されたセパレータでも同様に得られる。   As described above, in the nonaqueous electrolyte secondary battery having the wound electrode body shown in FIG. 4, even if the electrode mixture layer expands during charging and the thickness increases, local stretching of the separator occurs extremely. It is difficult to cause local narrowing between the positive and negative electrodes. Therefore, an internal short circuit due to intensive deposition of metal accompanying charging / discharging can be effectively prevented. In addition, this effect can be similarly obtained even with a thinned separator.

なお、図４においては、説明の便宜上、巻回中心３Ｃに関し、内側正極集電体露出部の始点６ｉｂ（ｓ）と外側負極集電体露出部の始点７ｏｂ（ｓ）とのなす角度をθ１、外側負極集電体露出部の始点７ｏｂ（ｓ）と両側正極集電体露出部の始点６ｂ（ｓ）とのなす角度をθ２、両側正極集電体露出部の始点６ｂ（ｓ）と両側負極集電体露出部の始点７ｂ（ｓ）とのなす角度をθ３、両側負極集電体露出部の始点７ｂ（ｓ）と負極リードの始点１３（ｓ）とのなす角度をθ４、負極リードの始点１３（ｓ）と内側正極集電体露出部の始点６ｉｂ（ｓ）とのなす角度をθ５と表示した。
実施例１〜３は、かかる角度が異なる以外は同一の構成を有するものであり、かかる角度の詳細を表１に示す。 In FIG. 4, for convenience of explanation, an angle formed between the start point 6 ib (s) of the inner positive electrode current collector exposed portion and the start point 7 obs (s) of the outer negative electrode current collector exposed portion with respect to the winding center 3C is θ1. , The angle formed by the start point 7ob (s) of the outer negative electrode current collector exposed portion and the start point 6b (s) of the both side positive electrode current collector exposed portion is θ2, and the start point 6b (s) of the both side positive electrode current collector exposed portion and the both sides The angle formed between the start point 7b (s) of the negative electrode current collector exposed portion is θ3, the angle formed between the start point 7b (s) of the negative electrode current collector exposed portion and the start point 13 (s) of the negative electrode lead is θ4, and the negative electrode lead The angle formed between the start point 13 (s) of the electrode and the start point 6 ib (s) of the exposed portion of the inner positive electrode current collector is indicated as θ5.
Examples 1 to 3 have the same configuration except that the angles are different. Table 1 shows details of the angles.

Figure 0005034418
Figure 0005034418

（実施例４〜６）
実施例１〜３と同様の操作を繰り返し、各例の非水電解質二次電池を得た。
図５は、実施例４〜６の非水電解質二次電池の概略的な横断面を示す模式的横断面図であり、巻回電極体の巻回終端近傍を示しているが、セパレータは図示していない。
なお、以下、上記と同様の部材・要素には同一符号を付し、その説明を省略する。 (Examples 4 to 6)
The same operation as in Examples 1 to 3 was repeated to obtain the nonaqueous electrolyte secondary battery of each example.
FIG. 5 is a schematic cross-sectional view showing a schematic cross-section of the nonaqueous electrolyte secondary batteries of Examples 4 to 6 and shows the vicinity of the winding end of the wound electrode body, but the separator is a figure. Not shown.
Hereinafter, the same members / elements as those described above are denoted by the same reference numerals, and the description thereof is omitted.

図５に示す巻回電極体３１において、正極６は、巻回終端の方向に沿って、延在した外側正極集電体露出部６ｏｂと延在した両側正極集電体露出部６ｂとがこの順で連続した領域を有し、それぞれの始点は符号６ｏｂ（ｓ）と６ｂ（ｓ）で表されている
一方、負極７は、巻回終端の方向に沿って、延在した外側負極集電体露出部７ｏｂと延在した両側負極集電体露出部７ｂとがこの順で連続した領域を有し、それぞれの始点は符号７ｏｂ（ｓ）と７ｂ（ｓ）で表されている。 In the spirally wound electrode body 31 shown in FIG. 5, the positive electrode 6 has an outer positive electrode collector exposed portion 6ob that extends and a positive electrode collector exposed portion 6b that extends on both sides along the direction of the winding end. The negative electrode 7 has an outer negative electrode current collector extending along the direction of the winding end, while the starting points are represented by reference numerals 6ob (s) and 6b (s). The body exposed portion 7ob and the extended negative electrode current collector exposed portion 7b have a continuous region in this order, and the respective starting points are represented by reference numerals 7ob (s) and 7b (s).

図５に示すように、この巻回電極体３１でも、上述の外側正極集電体露出部の始点６ｏｂ（ｓ）、両側正極集電体露出部の始点６ｂ（ｓ）、外側負極集電体露出部の始点７ｏｂ（ｓ）、両側負極集電体露出部の始点７ｂ（ｓ）、及び負極リードの始点１３（ｓ）が、巻回中心３Ｃを中心とするそれぞれ別個の半径上に位置している。
よって、この巻回電極体３１においても、上記図４に示す巻回電極体３０と同様の効果が得られる。 As shown in FIG. 5, this wound electrode body 31 also has the above-described outer positive current collector exposed portion start point 6 obs (s), both positive electrode current collector exposed portion start points 6 b (s), outer negative electrode current collector. The start point 7ob (s) of the exposed portion, the start point 7b (s) of the negative electrode current collector exposed portion, and the start point 13 (s) of the negative electrode lead are located on different radii centering on the winding center 3C. ing.
Therefore, also in this spirally wound electrode body 31, the same effect as that of the spirally wound electrode body 30 shown in FIG. 4 is obtained.

なお、図５においては、説明の便宜上、巻回中心３Ｃに関し、外側正極集電体露出部の始点６ｏｂ（ｓ）と両側負極集電体露出部の始点７ｂ（ｓ）とのなす角度をθ６、両側負極集電体露出部の始点７ｂ（ｓ）と負極リードの始点１３（ｓ）とのなす角度をθ７、負極リードの始点１３（ｓ）と両側正極集電体露出部の始点６ｂ（ｓ）とのなす角度をθ８、両側正極集電体露出部の始点６ｂ（ｓ）と外側負極集電体露出部の始点７ｏｂ（ｓ）とのなす角度をθ９、外側負極集電体露出部の始点７ｏｂ（ｓ）と外側正極集電体露出部の始点６ｏｂ（ｓ）とのなす角度をθ１０と表示した。
実施例４〜６は、かかる角度が異なる以外は同一の構成を有するものであり、かかる角度の詳細を表２に示す。 In FIG. 5, for convenience of explanation, the angle formed between the starting point 6ob (s) of the outer positive electrode current collector exposed portion and the starting point 7b (s) of the negative electrode current collector exposed portion with respect to the winding center 3C is θ6. The angle between the start point 7b (s) of the negative electrode current collector exposed portion and the start point 13 (s) of the negative electrode lead is θ7, the start point 13 (s) of the negative electrode lead and the start point 6b of the positive electrode current collector exposed portion of both sides ( s) is θ8, the angle between the start point 6b (s) of the both-side positive electrode current collector exposed portion and the start point 7ob (s) of the outer negative electrode current collector exposed portion is θ9, and the outer negative electrode current collector exposed portion The angle between the starting point 7ob (s) and the starting point 6ob (s) of the exposed portion of the outer positive electrode current collector is indicated as θ10.
Examples 4 to 6 have the same configuration except that the angles are different, and Table 2 shows the details of the angles.

Figure 0005034418
Figure 0005034418

（比較例１）
上記同様の操作を繰り返し、本例の非水電解質二次電池を得た。
図６は、従来の非水電解質二次電池の概略的な横断面を示す模式的横断面図であり、巻回電極体の巻回終端近傍を示しているが、セパレータは図示していない。
図６に示す巻回電極体３００において、正極６は、巻回終端の方向に沿って、延在した両側正極集電体露出部６ｂ、及びその始点６ｂ（ｓ）を有しているが、図４や図５に示す巻回電極体とは異なり、内側又は外側の片面が露出した集電体部分を有していない。
一方、負極７は、巻回終端の方向に沿って、延在した外側負極集電体露出部７ｏｂと延在した両側負極集電体露出部７ｂとがこの順で連続した領域を有し、それぞれの始点は符号７ｏｂ（ｓ）と７ｂ（ｓ）で表されている。 (Comparative Example 1)
The same operation as described above was repeated to obtain the nonaqueous electrolyte secondary battery of this example.
FIG. 6 is a schematic cross-sectional view showing a schematic cross-section of a conventional nonaqueous electrolyte secondary battery, showing the vicinity of the winding end of the wound electrode body, but the separator is not shown.
In the spirally wound electrode body 300 shown in FIG. 6, the positive electrode 6 has both side positive electrode current collector exposed portions 6b extending along the direction of the winding end, and its starting point 6b (s). Unlike the spirally wound electrode body shown in FIGS. 4 and 5, it does not have a current collector portion where one side of the inner side or the outer side is exposed.
On the other hand, the negative electrode 7 has a region in which the extended outer negative electrode collector exposed portion 7ob and the extended negative electrode collector exposed portion 7b extend in this order along the winding end direction. The respective starting points are represented by reference numerals 7ob (s) and 7b (s).

図６に示すように、この巻回電極体３００では、正極６が片面が露出した集電体部分を有しておらず、内側と外側に正極合剤層６ｉ，６ｏを有する正極６から直ちに両側正極集電体露出部６ｂが突出している。よって、両側正極集電体露出部の始点６ｂ（ｓ）において巻回中心３Ｃの半径方向に比較的大きな段差を生ずる。
また、外側負極集電体露出部の始点７ｏｂ（ｓ）と両側負極集電体露出部の始点７ｂ（ｓ）とが、巻回中心３Ｃの同一半径上に位置しており、ここでも大きな段差を生じている。 As shown in FIG. 6, in this wound electrode body 300, the positive electrode 6 does not have a current collector portion with one surface exposed, and immediately from the positive electrode 6 having the positive electrode mixture layers 6 i and 6 o on the inner side and the outer side. The positive electrode current collector exposed portions 6b on both sides protrude. Therefore, a relatively large step is generated in the radial direction of the winding center 3C at the starting point 6b (s) of the exposed portion of the positive electrode current collector on both sides.
In addition, the start point 7ob (s) of the outer negative electrode current collector exposed portion and the start point 7b (s) of the negative electrode current collector exposed portion on both sides are located on the same radius of the winding center 3C. Has produced.

このような巻回構造を有する本例の非水電解質二次電池では、充電の際のセパレータの局所的引き伸ばしに起因する電極間の局所的狭小化が発生し易く、よって、充放電に伴うメタルの集中的析出などよる内部短絡も引き起こす可能性がある。
なお、図６においては、説明の便宜上、巻回中心３Ｃに関し、両側正極集電体露出部の始点６ｂ（ｓ）と外側負極集電体露出部の始点７ｏｂ（ｓ）とのなす角度をθ１１、外側負極集電体露出部の始点７ｏｂ（ｓ）と負極リードの始点１３（ｓ）とのなす角度をθ１２、負極リードの始点１３（ｓ）と両側正極集電体露出部の始点６ｂ（ｓ）とのなす角度をθ１３と表示した。詳細を表１及び表２に併記した。 In the non-aqueous electrolyte secondary battery of this example having such a winding structure, local narrowing between the electrodes due to local stretching of the separator at the time of charging is likely to occur. Internal short-circuiting due to intensive precipitation of the metal may also occur.
In FIG. 6, for convenience of explanation, the angle formed between the starting point 6b (s) of the positive electrode collector exposed portion on both sides and the starting point 7ob (s) of the exposed negative electrode collector portion is θ11 with respect to the winding center 3C. The angle formed between the start point 7ob (s) of the outer negative electrode collector exposed portion and the start point 13 (s) of the negative electrode lead is θ12, and the start point 13 (s) of the negative electrode lead and the start point 6b of the both sides positive electrode current collector exposed portion ( The angle formed by s) was indicated as θ13. Details are shown in Tables 1 and 2.

［性能評価］
各例の非水電解質二次電池につき、最大電流０．７Ｃ下、４．２Ｖ定電圧−定電流充電（５０ｍＡカット）の条件下で充電を行い、４５℃下でエージングを行った。得られたセルに対し、電圧３．０Ｖまでの捨て放電後、電池電圧４．２Ｖでの充電後に３．０Ｖ迄放電するサイクル試験を行い、得られた結果を図７及び図８に示すとともに、表１及び表２に５００サイクル劣化率を併記した。 [Performance evaluation]
The non-aqueous electrolyte secondary battery of each example was charged under the conditions of maximum current 0.7C, 4.2V constant voltage-constant current charging (50 mA cut), and aging was performed at 45 ° C. The obtained cell was subjected to a cycle test of discharging to 3.0 V after charging at a battery voltage of 4.2 V after discharging to a voltage of 3.0 V, and the results obtained are shown in FIGS. 7 and 8. Table 1 and Table 2 also show the 500 cycle deterioration rate.

図７及び図８より、巻回電極体最外周部の電極形状が正負極とも片面合剤塗布形状（内側ないし外側集電体露出部）を有し、厚みによる段差がより小さく、且つ巻回電極体の円周径に対して分散された構造を有する方が、充電に伴う電極体の膨張によって生じる外周部への押し圧力によりセパレータが局所的に引き延ばされる現象、即ち局所的な極間距離の狭小化が発生するのを抑制するため、内部短絡を抑制してサイクル特性の低下を改善し得ることが分かる。   7 and 8, the electrode shape of the outermost periphery of the wound electrode body has a single-sided mixture application shape (inner side or outer current collector exposed portion) for both the positive and negative electrodes, the step difference due to the thickness is smaller, and the winding is Phenomenon in which the separator is locally stretched by the pressing force to the outer peripheral part caused by the expansion of the electrode body accompanying charging, that is, the structure having a structure dispersed with respect to the circumferential diameter of the electrode body, that is, the local gap In order to suppress the occurrence of the narrowing of the distance, it can be seen that the internal short circuit can be suppressed and the deterioration of the cycle characteristics can be improved.

以上、本発明を好適実施形態及び実施例により詳細に説明したが、本発明はこれらの実施形態や実施例に限定されるものではなく、本発明の要旨の範囲内において種々の変形が可能である。
例えば、正極を第１電極、負極を第２電極として説明したが、これらを置換した構成も本発明の範囲に含まれる。 As mentioned above, although this invention was demonstrated in detail by preferred embodiment and an Example, this invention is not limited to these embodiment and an Example, A various deformation | transformation is possible within the range of the summary of this invention. is there.
For example, although the positive electrode has been described as the first electrode and the negative electrode as the second electrode, configurations in which these are replaced are also included in the scope of the present invention.

本発明の非水電解質二次電池の一実施形態を示す縦断面図である。It is a longitudinal cross-sectional view which shows one Embodiment of the nonaqueous electrolyte secondary battery of this invention. 本発明の非水電解質二次電池に係る巻回電極体を示す斜視図である。It is a perspective view which shows the winding electrode body which concerns on the nonaqueous electrolyte secondary battery of this invention. 巻回電極体を横方向に切断した断面図である。It is sectional drawing which cut | disconnected the wound electrode body in the horizontal direction. 本発明の非水電解質二次電池の一実施例の概略的な横断面を示す模式的横断面図である。1 is a schematic cross-sectional view showing a schematic cross-section of one embodiment of a nonaqueous electrolyte secondary battery of the present invention. 本発明の非水電解質二次電池の他の実施例の概略的な横断面を示す模式的横断面図である。It is a typical cross section which shows the schematic cross section of the other Example of the nonaqueous electrolyte secondary battery of this invention. 従来の非水電解質二次電池の概略的な横断面を示す模式的横断面図である。It is a typical cross section which shows the schematic cross section of the conventional nonaqueous electrolyte secondary battery. 非水電解質二次電池のサイクル特性を示すグラフである。It is a graph which shows the cycling characteristics of a nonaqueous electrolyte secondary battery. 非水電解質二次電池のサイクル特性を示すグラフである。It is a graph which shows the cycling characteristics of a nonaqueous electrolyte secondary battery.

符号の説明Explanation of symbols

１…リチウムイオン二次電池（非水電解質二次電池）、２…電池缶、３，３０，３１，３００…巻回電極体、３Ｃ…巻回中心、４…安全弁装置、５…端子板、６…正極、６ｍ…正極集電体、６ｉ，６ｏ…正極合剤層、６ｉｂ…内側正極集電体露出部、６ｏｂ…外側正極集電体露出部、６ｂ…両側正極集電体露出部、７…負極、７ｍ…負極集電体、７ｉ，７ｏ…負極合剤層、７ｉｂ…内側負極集電体露出部、７ｏｂ…外側負極集電体露出部、７ｂ…両側負極集電体露出ｂ、８，９…セパレータ、１４…センタピン、１４ａ…中央穴、１７…ガスケット、１８…開裂弁、１９…遮断弁 DESCRIPTION OF SYMBOLS 1 ... Lithium ion secondary battery (nonaqueous electrolyte secondary battery), 2 ... Battery can, 3, 30, 31, 300 ... Winding electrode body, 3C ... Winding center, 4 ... Safety valve apparatus, 5 ... Terminal board, 6 ... Positive electrode, 6m ... Positive electrode current collector, 6i, 6o ... Positive electrode mixture layer, 6ib ... Inner positive electrode current collector exposed part, 6ob ... Outer positive electrode current collector exposed part, 6b ... Both side positive electrode current collector exposed part, 7 ... Negative electrode, 7m ... Negative electrode current collector, 7i, 7o ... Negative electrode mixture layer, 7ib ... Inner negative electrode current collector exposed portion, 7ob ... Outer negative electrode current collector exposed portion, 7b ... Both sides negative electrode current collector exposed b, 8, 9 ... Separator, 14 ... Center pin, 14a ... Center hole, 17 ... Gasket, 18 ... Cleavage valve, 19 ... Shut-off valve

Claims (7)

極性の異なる第１電極と第２電極をセパレータを介して巻回して成る巻回電極体と、非水電解質組成物と、これらを収容する外装体を備え、
上記第１電極が、帯状をなす第１電極集電体の内周面に内側第１電極合剤層を有するとともに、その外周面に外側第１電極合剤層を有し、
上記第２電極が、帯状をなす第２電極集電体の内周面に内側第２電極合剤層を有するとともに、その外周面に外側第２電極合剤層を有する、非水電解質二次電池において、
上記巻回電極体は、その巻回中心に対して、上記第１電極が内側で、上記第２電極が外側になるように巻回されており、
上記第２電極が、巻回終端の方向に沿って、上記外側第２電極合剤層を有さない外側第２電極集電体露出部と、上記内側第２電極合剤層及び上記外側第２電極合剤層を有さない両側第２電極集電体露出部を、この順で有し、
上記第１電極が、巻回終端の方向に沿って、上記内側第１電極合剤層を有さない内側第１電極集電体露出部と、上記内側第１電極合剤層及び上記外側第１電極合剤層を有さない両側第１電極集電体露出部を、この順で有し、
上記外側第２電極集電体露出部の始点、上記内側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、
ことを特徴とする非水電解質二次電池。 A wound electrode body formed by winding a first electrode and a second electrode with different polarities through a separator, a nonaqueous electrolyte composition, and an exterior body that accommodates these,
The first electrode has an inner first electrode mixture layer on the inner peripheral surface of the first electrode current collector having a strip shape, and an outer first electrode mixture layer on the outer peripheral surface thereof,
The non-aqueous electrolyte secondary, wherein the second electrode has an inner second electrode mixture layer on the inner peripheral surface of the second electrode current collector having a strip shape and an outer second electrode mixture layer on the outer peripheral surface. In batteries,
The wound electrode body is wound such that the first electrode is on the inner side and the second electrode is on the outer side with respect to the winding center,
The second electrode has an outer second electrode current collector exposed portion not having the outer second electrode mixture layer, the inner second electrode mixture layer, and the outer second electrode along the winding end direction. Having both side second electrode current collector exposed portions not having a two-electrode mixture layer in this order,
The first electrode has an inner first electrode current collector exposed portion that does not have the inner first electrode mixture layer, the inner first electrode mixture layer, and the outer first electrode along the winding end direction. Having both side first electrode current collector exposed portions not having one electrode mixture layer in this order,
The start point of the outer second electrode current collector exposed portion, the start point of the inner first electrode current collector exposed portion, the start point of the both side second electrode current collector exposed portion, and the both side first electrode current collector exposed portion Is located on a separate radius of the winding center,
A non-aqueous electrolyte secondary battery. 上記外装体の内周面に、上記第２電極と上記外装体とを電気接続する第２電極リードを有し、
この第２電極リード、上記外側第２電極集電体露出部の始点、上記内側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び両側上記第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、
ことを特徴とする請求項１に記載の非水電解質二次電池。 A second electrode lead for electrically connecting the second electrode and the exterior body on the inner peripheral surface of the exterior body;
The second electrode lead, the start point of the outer second electrode current collector exposed portion, the start point of the inner first electrode current collector exposed portion, the start point of the second electrode current collector exposed portion on both sides, and the first side on both sides The starting point of the electrode current collector exposed portion is located on a separate radius of the winding center,
The non-aqueous electrolyte secondary battery according to claim 1. 上記巻回電極体をその巻回中心を回転中心とする回転体とみなした場合、上記第２電極リード、上記外側第２電極集電体露出部の始点、上記内側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、当該回転体に内接する正五角形の各頂点と上記巻回中心を結ぶ線分上に、それぞれ別個に位置している、ことを特徴とする請求項２に記載の非水電解質二次電池。   When the wound electrode body is regarded as a rotating body having the winding center as the rotation center, the second electrode lead, the start point of the outer second electrode current collector exposed portion, the inner first electrode current collector exposure The starting point of the two-sided second electrode current collector exposed portion and the starting point of the two-sided first electrode current collector exposed portion connect each vertex of the regular pentagon inscribed in the rotating body and the winding center. The nonaqueous electrolyte secondary battery according to claim 2, wherein the nonaqueous electrolyte secondary battery is separately located on the line segment. 極性の異なる第１電極と第２電極をセパレータを介して巻回して成る巻回電極体と、非水電解質組成物と、これらを収容する外装体を備え、
上記第１電極が、帯状をなす第１電極集電体の内周面に内側第１電極合剤層を有するとともに、その外周面に外側第１電極合剤層を有し、
上記第２電極が、帯状をなす第２電極集電体の内周面に内側第２電極合剤層を有するとともに、その外周面に外側第２電極合剤層を有する、非水電解質二次電池において、
上記巻回電極体は、その巻回中心に対して、上記第１電極が内側で、上記第２電極が外側になるように巻回されており、
上記第２電極が、巻回終端の方向に沿って、上記外側第２電極合剤層を有さない外側第２電極集電体露出部と、上記内側第２電極合剤層及び上記外側第２電極合剤層を有さない両側第２電極集電体露出部を、この順で有し、
上記第１電極が、巻回終端の方向に沿って、上記外側第１電極合剤層を有さない外側第１電極集電体露出部と、上記内側第１電極合剤層及び上記外側第１電極合剤層を有さない両側第１電極集電体露出部を、この順で有し、
上記外側第２電極集電体露出部の始点、上記外側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、
ことを特徴とする非水電解質二次電池。 A wound electrode body formed by winding a first electrode and a second electrode with different polarities through a separator, a nonaqueous electrolyte composition, and an exterior body that accommodates these,
The first electrode has an inner first electrode mixture layer on the inner peripheral surface of the first electrode current collector having a strip shape, and an outer first electrode mixture layer on the outer peripheral surface thereof,
The non-aqueous electrolyte secondary, wherein the second electrode has an inner second electrode mixture layer on the inner peripheral surface of the second electrode current collector having a strip shape and an outer second electrode mixture layer on the outer peripheral surface. In batteries,
The wound electrode body is wound such that the first electrode is on the inner side and the second electrode is on the outer side with respect to the winding center,
The second electrode has an outer second electrode current collector exposed portion not having the outer second electrode mixture layer, the inner second electrode mixture layer, and the outer second electrode along the winding end direction. Having both side second electrode current collector exposed portions not having a two-electrode mixture layer in this order,
The first electrode has an outer first electrode current collector exposed portion that does not have the outer first electrode mixture layer, the inner first electrode mixture layer, and the outer first electrode along the winding end direction. Having both side first electrode current collector exposed portions not having one electrode mixture layer in this order,
The start point of the outer second electrode current collector exposed portion, the start point of the outer first electrode current collector exposed portion, the start point of the both side second electrode current collector exposed portion, and the both side first electrode current collector exposed portion Is located on a separate radius of the winding center,
A non-aqueous electrolyte secondary battery. 上記外装体の内周面に、上記第２電極と上記外装体とを電気接続する第２電極リードを有し、
この第２電極リード、上記外側第２電極集電体露出部の始点、上記外側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び両側上記第１電極集電体露出部の始点が、上記巻回中心の別個の半径上に位置している、
ことを特徴とする請求項４に記載の非水電解質二次電池。 A second electrode lead for electrically connecting the second electrode and the exterior body on the inner peripheral surface of the exterior body;
The second electrode lead, the starting point of the outer second electrode current collector exposed portion, the starting point of the outer first electrode current collector exposed portion, the starting point of the both-side second electrode current collector exposed portion, and the both side first The starting point of the electrode current collector exposed portion is located on a separate radius of the winding center,
The nonaqueous electrolyte secondary battery according to claim 4 . 上記巻回電極体をその巻回中心を回転中心とする回転体とみなした場合、上記第２電極リード、上記外側第２電極集電体露出部の始点、上記外側第１電極集電体露出部の始点、上記両側第２電極集電体露出部の始点、及び上記両側第１電極集電体露出部の始点が、当該回転体に内接する正五角形の各頂点と上記巻回中心を結ぶ線分上に、それぞれ別個に位置している、ことを特徴とする請求項５に記載の非水電解質二次電池。 When the wound electrode body is regarded as a rotating body having the winding center as a rotation center, the second electrode lead, the start point of the outer second electrode current collector exposed portion, the outer first electrode current collector exposure The starting point of the two-sided second electrode current collector exposed portion and the starting point of the two-sided first electrode current collector exposed portion connect each vertex of the regular pentagon inscribed in the rotating body and the winding center. The nonaqueous electrolyte secondary battery according to claim 5 , wherein the nonaqueous electrolyte secondary battery is individually located on the line segment. 上記第１電極が正極であり、上記第２電極が負極であることを特徴とする請求項１又は請求項４に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to claim 1 or 4 , wherein the first electrode is a positive electrode and the second electrode is a negative electrode.
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