JP2010161001A - Electrochemical cell - Google Patents

Electrochemical cell Download PDF

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JP2010161001A
JP2010161001A JP2009003325A JP2009003325A JP2010161001A JP 2010161001 A JP2010161001 A JP 2010161001A JP 2009003325 A JP2009003325 A JP 2009003325A JP 2009003325 A JP2009003325 A JP 2009003325A JP 2010161001 A JP2010161001 A JP 2010161001A
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electrode
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resistance
electrochemical cell
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JP5289983B2 (en
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Shizukuni Yada
静邦 矢田
Shunji Kinoshita
俊二 木下
Mayumi Kuriyama
真由美 久里山
Hisashi Satake
久史 佐竹
Hajime Kinoshita
肇 木下
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Kri Inc
株式会社Kri
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    • YGENERAL 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

<P>PROBLEM TO BE SOLVED: To provide an electrochemical cell capable of simultaneously separating simply and accurately inner resistances such as a battery and a capacitor or the like into each of resistances of a cathode, an anode and an electrolyte solution (separator). <P>SOLUTION: The electrochemical cell comprises a cathode, an anode and at least two reference electrodes, and at least one reference electrode is a positive reference electrode arranged near on a positive electrode surface, and at least one reference electrode is a negative reference electrode arranged near on a negative electrode surface, and the width (W) of the reference electrode is 0.15 mm or less, and the distance (d1) between the cathode and the positive reference electrode arranged on the positive electrode surface and the distance (d2) between the anode and the negative reference electrode arranged on the negative electrode surface are W or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、電池、キャパシタ等の内部抵抗を正極、負極、電解液(セパレータ)の各抵抗に、簡便かつ精度良く同時に分離可能な電気化学セルに関する。   The present invention relates to an electrochemical cell that can easily and accurately simultaneously separate internal resistances of batteries, capacitors, and the like into resistances of a positive electrode, a negative electrode, and an electrolyte (separator).
近年、ハイブリッド電気自動車、瞬時停電バックアップ等の大電流負荷用途に向け、最先端蓄電デバイスであるリチウムイオン電池、リチウムイオンキャパシタ、電気二重層キャパシタ等の開発が加速している。この開発において、蓄電デバイスの入出力特性は最も重要な特性となり、迅速かつ有用な入出力特性評価、解析手法が求められている。従来、入出力特性は、蓄電デバイスに複数の充電電流(入力)あるいは放電電流(出力)を印加することにより得られる充電カーブあるいは放電カーブを解析・計算し評価されており、その評価は煩雑かつ手間のかかる作業であった。矢田は、入出力特性と内部抵抗を直接に関係づける評価手法として、直流電流印加を休止した時の電圧変化から内部抵抗の時間依存性を測定する直流内部抵抗測定法(電流休止法)の適用を提案している(非特許文献1)。この非特許文献1において休止直後から1秒までの電圧変化から算出される抵抗を休止法抵抗の「オーム成分」、1秒以降の電圧変化から算出される抵抗を休止法抵抗の「平衡成分」と定義されている。この電流休止法によれば、この方法により得られる直流内部抵抗(休止法抵抗)の時間変化を用いて、実際の入出力特性を予測することが可能である(非特許文献2、3)。このように直流内部抵抗(休止法抵抗)は実際の入出力特性と密接に関係するものであり、その評価・解析は特に高出力蓄電デバイスでは非常に重要となってきている。   In recent years, development of lithium-ion batteries, lithium-ion capacitors, electric double layer capacitors, etc., which are state-of-the-art power storage devices, has been accelerated toward high-current load applications such as hybrid electric vehicles and instantaneous power failure backups. In this development, the input / output characteristics of power storage devices are the most important characteristics, and rapid and useful input / output characteristics evaluation and analysis methods are required. Conventionally, input / output characteristics have been evaluated by analyzing and calculating a charge curve or discharge curve obtained by applying a plurality of charging currents (inputs) or discharging currents (outputs) to an electricity storage device. It was a laborious work. As an evaluation method that directly correlates input / output characteristics and internal resistance, Yada applied the DC internal resistance measurement method (current pause method) that measures the time dependence of internal resistance from the voltage change when DC current application was paused. (Non-Patent Document 1). In this Non-Patent Document 1, the resistance calculated from the voltage change from immediately after the pause to 1 second is the “ohm component” of the pause method resistance, and the resistance calculated from the voltage change after the second is the “balance component” of the pause method resistance. It is defined as According to this current pause method, it is possible to predict the actual input / output characteristics using the time change of the DC internal resistance (pause method resistance) obtained by this method (Non-Patent Documents 2 and 3). As described above, the direct current internal resistance (resting method resistance) is closely related to the actual input / output characteristics, and the evaluation / analysis thereof has become very important particularly in a high-power storage device.
一方、蓄電デバイスの内部抵抗には,正極に起因する内部抵抗(正極抵抗)、負極に起因する内部抵抗(負極抵抗)、そして,電解液を含むセパレータに起因する内部抵抗(セパレータ抵抗)がある。各抵抗は蓄電デバイスの入出力特性を決定する基本要素である。従来、これら抵抗の解析は正極、負極、セパレータを個別で解析し、この解析情報からデバイス内における上記各抵抗を推定していた。これは内部抵抗、特に入出力特性と直接関係づけられる直流内部抵抗(休止法抵抗)を、デバイス内で分離し、かつ、同時に各抵抗(正極抵抗、負極抵抗、セパレータ抵抗)を評価することが難しいことによるものである。この課題に対し、矢田は非特許文献1において、四極セルによる分離手法を提案、報告している。この四極セルの構造は正極、負極以外に正極に近い位置に配置された正参照極、負極に近い位置に配置された負参照極の2つの参照極を有している。この四極セルを用いれば、正極抵抗、負極抵抗、セパレータ抵抗を、同時に分離することが可能とされており、この四極セルに対し、例えば、上記電流休止法を適用すれば、入出力特性と直接関係づけられるデバイス全体の休止法抵抗を、正極の休止法抵抗、負極の休止法抵抗、セパレータの休止法抵抗に分離することができ、より詳細な抵抗解析(入出力特性解析)が可能となる。   On the other hand, the internal resistance of the electricity storage device includes an internal resistance due to the positive electrode (positive electrode resistance), an internal resistance due to the negative electrode (negative electrode resistance), and an internal resistance due to the separator containing the electrolytic solution (separator resistance). . Each resistor is a basic element that determines the input / output characteristics of the electricity storage device. Conventionally, in the analysis of these resistances, the positive electrode, the negative electrode, and the separator are individually analyzed, and the respective resistances in the device are estimated from this analysis information. This separates the internal resistance, especially the DC internal resistance (quiescent resistance), which is directly related to the input / output characteristics, within the device and at the same time evaluates each resistance (positive resistance, negative resistance, separator resistance). This is due to difficulties. In response to this problem, Yada proposed and reported a separation method using a quadrupole cell in Non-Patent Document 1. In addition to the positive electrode and the negative electrode, the structure of this quadrupole cell has two reference electrodes, a positive reference electrode disposed near the positive electrode and a negative reference electrode disposed near the negative electrode. If this quadrupole cell is used, the positive electrode resistance, the negative electrode resistance, and the separator resistance can be separated at the same time. The associated quiescent resistance of the entire device can be separated into positive quiescent resistance, negative quiescent resistance, and separator quiescent resistance, allowing more detailed resistance analysis (input / output characteristic analysis). .
この四極セルに関して特許文献1には、正極、負極、及び少なくとも2つの参照極を有し、少なくとも1つの参照極は正極の近傍に位置し、少なくとも1つの他の参照極は負極の近傍に位置することを特徴とし、正極と負極との極間(D)が1mm以下であり、正極の近傍に位置する参照極と正極との距離、及び、負極の近傍に位置する参照極と負極との距離の少なくともいずれか一方が、D以下である電気化学セルが開示されている。特許文献1に開示されている具体例では、正極の近傍に位置する参照極の表面は正極表面より内側にあり、負極の近傍に位置する参照極の表面は負極表面より内側にある。しかし、このセルを実際組み立てた場合、参照極の位置決め(正極と正極の近傍に位置する参照極との位置関係・距離、あるいは、負極と負極の近傍に位置する参照極との位置関係・距離)が難しく、参照極の位置決めが容易であり、かつ、精度良く抵抗を分離可能な電気化学セルが必要とされていた。   With respect to this quadrupole cell, Patent Document 1 has a positive electrode, a negative electrode, and at least two reference electrodes, wherein at least one reference electrode is located in the vicinity of the positive electrode and at least one other reference electrode is located in the vicinity of the negative electrode. The distance (D) between the positive electrode and the negative electrode is 1 mm or less, the distance between the reference electrode and the positive electrode located in the vicinity of the positive electrode, and the reference electrode and the negative electrode located in the vicinity of the negative electrode. An electrochemical cell in which at least one of the distances is D or less is disclosed. In the specific example disclosed in Patent Document 1, the surface of the reference electrode located near the positive electrode is inside the positive electrode surface, and the surface of the reference electrode located near the negative electrode is inside the negative electrode surface. However, when this cell is actually assembled, positioning of the reference electrode (position relationship / distance between the positive electrode and the reference electrode located near the positive electrode, or position relationship / distance between the negative electrode and the reference electrode located near the negative electrode ) Is difficult, the positioning of the reference electrode is easy, and an electrochemical cell capable of accurately separating the resistance is required.
特開2005−19116号公報JP-A-2005-19116
上記のごとく、正極、負極、及び少なくとも2つの参照極を有し、少なくとも1つの参照極は正極の近傍に位置し、少なくとも1つの他の参照極は負極の近傍に位置する電気セルを用いて、蓄電デバイスの内部抵抗を、同時にデバイス内で分離し、各抵抗(正極抵抗、負極抵抗、セパレータ抵抗)を評価する手法が知られている。また、正極、負極及び少なくとも1つの正参照極と少なくとも1つの負参照極とを有し、正参照極は正極面上の近傍に、負参照極は負極面上の近傍に配置された四極セルの構造に関して非特許文献1に開示されている。このように、正参照極を正極面上の近傍に、負参照極を負極面上の近傍に配置した場合、正極抵抗、負極抵抗、セパレータ抵抗をデバイス内で同時に分離評価することが可能であり、参照極の位置決めは容易になるものの、各抵抗の測定精度、分離精度に課題があった。本発明の目的は電池、キャパシタ等の内部抵抗を正極、負極、電解液(セパレータ)の各抵抗を簡便にかつ精度良く同時に分離可能な電気化学セルを提供することにある。   As described above, using an electric cell having a positive electrode, a negative electrode, and at least two reference electrodes, wherein at least one reference electrode is located in the vicinity of the positive electrode and at least one other reference electrode is located in the vicinity of the negative electrode. A method is known in which the internal resistance of the electricity storage device is simultaneously separated in the device and each resistance (positive electrode resistance, negative electrode resistance, separator resistance) is evaluated. A quadrupole cell having a positive electrode, a negative electrode, and at least one positive reference electrode and at least one negative reference electrode, the positive reference electrode being disposed in the vicinity on the positive electrode surface, and the negative reference electrode being disposed in the vicinity on the negative electrode surface This structure is disclosed in Non-Patent Document 1. As described above, when the positive reference electrode is disposed in the vicinity of the positive electrode surface and the negative reference electrode is disposed in the vicinity of the negative electrode surface, the positive electrode resistance, the negative electrode resistance, and the separator resistance can be separately evaluated in the device. Although positioning of the reference electrode is facilitated, there are problems in measurement accuracy and separation accuracy of each resistor. An object of the present invention is to provide an electrochemical cell capable of easily and accurately separating internal resistances of a battery, a capacitor and the like from positive and negative electrodes and an electrolyte (separator).
本発明者は、上記の様な従来技術の問題点に留意しつつ研究を進めた結果、正極、負極及び少なくとも2つの参照極を有し、少なくとも1つの参照極は、正極面上の近傍に配置されている正参照極であり、少なくとも1つの参照極は、負極面上の近傍に配置されている負参照極である電気化学セルにおいて、参照極の形状、位置が特定条件内にあるとき、電池、キャパシタ等の内部抵抗を正極、負極、電解液(セパレータ)の各抵抗に簡便にかつ精度良く同時に分離可能であることを見出し本発明に至った。   As a result of conducting research while paying attention to the problems of the prior art as described above, the present inventor has a positive electrode, a negative electrode, and at least two reference electrodes, and at least one reference electrode is located near the positive electrode surface. In an electrochemical cell that is a positive reference electrode that is disposed and at least one reference electrode is a negative reference electrode disposed in the vicinity on the negative electrode surface, when the shape and position of the reference electrode are within specific conditions The present inventors have found that internal resistances of batteries, capacitors, etc. can be easily and accurately separated into positive, negative, and electrolytic solution (separator) resistances at the same time.
すなわち本発明は、以下の構成からなることを特徴とし、上記課題を解決するものである。   That is, the present invention is characterized by having the following configuration and solves the above problems.
(1)正極、負極及び少なくとも2つの参照極を有する電気化学セルであって、少なくとも1つの参照極は、正極面上の近傍に配置されている正参照極であり、少なくとも1つの参照極は、負極面上の近傍に配置されている負参照極であり、前記参照極の幅(W)が0.15mm以下、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)がW以上であることを特徴とする電気化学セル。
この構成により、電池、キャパシタ等の内部抵抗を正極、負極、電解液(セパレータ)の各抵抗に簡便かつ精度良く同時に分離可能である。前記の正極面上あるいは負極面上の近傍とは正極と負極との間の任意の位置で、正参照極及び負参照極の一部、あるいは、全部が各々正極面上、負極面上にあることをいう。また、前記のd1及びd2は、各々正極面(セパレータ側の電極面)と正参照極の最短距離、負極面(セパレータ側の電極面)と負参照極の最短距離である。
前記参照極の幅(W)は、前記参照極が製作可能な幅以上で0.15mm以下であればよいが、測定する抵抗が小さい場合には、前記参照極の幅(W)を小さくすれば、より精度良く内部抵抗の測定が可能になる。すなわち、前記参照極の幅(W)は、前記参照極製作可能な幅以上で0.1mm以下であるのが好ましく、より好ましくは0.08mm以下である。
(1) An electrochemical cell having a positive electrode, a negative electrode, and at least two reference electrodes, wherein at least one reference electrode is a positive reference electrode disposed in the vicinity on the positive electrode surface, and at least one reference electrode is , A negative reference electrode disposed in the vicinity of the negative electrode surface, the width (W) of the reference electrode being 0.15 mm or less, a distance (d1) between the positive electrode and the positive reference electrode disposed on the positive electrode surface, and An electrochemical cell, wherein a distance (d2) between the negative electrode and the negative reference electrode disposed on the negative electrode surface is W or more.
With this configuration, the internal resistance of a battery, a capacitor, or the like can be easily and accurately simultaneously separated into each resistance of the positive electrode, the negative electrode, and the electrolytic solution (separator). The vicinity on the positive electrode surface or the negative electrode surface is an arbitrary position between the positive electrode and the negative electrode, and some or all of the positive reference electrode and the negative reference electrode are on the positive electrode surface and the negative electrode surface, respectively. That means. The d1 and d2 are the shortest distance between the positive electrode surface (the separator-side electrode surface) and the positive reference electrode, and the shortest distance between the negative electrode surface (the separator-side electrode surface) and the negative reference electrode.
The width (W) of the reference electrode may be not less than a width that allows the reference electrode to be manufactured and not more than 0.15 mm. However, if the resistance to be measured is small, the width (W) of the reference electrode is reduced. As a result, the internal resistance can be measured with higher accuracy. That is, the width (W) of the reference electrode is preferably not less than the width that allows the reference electrode to be manufactured and not more than 0.1 mm, and more preferably not more than 0.08 mm.
(2)前記電気化学セルにおいて参照極の厚み(H)が0.15mm以下であることを特徴とする電気化学セル。
前記参照極の厚み(H)も製作可能であれば、できるだけ薄い方が好ましい。(2)の構成によれば、特に、電解液(セパレータ)の抵抗の分離精度を更に向上することが可能である。
(2) In the electrochemical cell, the thickness (H) of the reference electrode is 0.15 mm or less.
If the thickness (H) of the reference electrode can also be manufactured, it is preferable that it is as thin as possible. According to the configuration of (2), it is possible to further improve the separation accuracy of the resistance of the electrolytic solution (separator).
(3)前記電気化学セルにおいて正参照極及び負参照極の全部が正極あるいは負極の電極端面より内側に配置されることを特徴とする電気化学セル。
(3)の構成によれば、特に、非特許文献1に記載の休止法抵抗における「オーム成分」の測定精度を更に向上することが可能である。
(3) The electrochemical cell characterized in that in the electrochemical cell, all of the positive reference electrode and the negative reference electrode are arranged on the inner side of the electrode end face of the positive electrode or the negative electrode.
According to the configuration of (3), in particular, it is possible to further improve the measurement accuracy of the “ohm component” in the pause method resistance described in Non-Patent Document 1.
(4)前記電気化学セルにおいて参照極の長さ(L)が5mm以下であることを特徴とする電気化学セル。
前記参照極の長さ(L)も製作可能であれば、できるだけ短い方が好ましい。(4)の構成によれば、特に、非特許文献1に記載の休止法抵抗における「平衡成分」の測定精度を更に向上することが可能である。
(4) The electrochemical cell characterized in that the reference electrode has a length (L) of 5 mm or less in the electrochemical cell.
As long as the length (L) of the reference electrode can be manufactured, it is preferable that the length is as short as possible. According to the configuration of (4), in particular, it is possible to further improve the measurement accuracy of the “equilibrium component” in the pause method resistance described in Non-Patent Document 1.
(5)正参照極及び/又は負参照極が導電性基材上に参照極材料を電気化学的に析出させたものであることを特徴とする電気化学セル。
(5)の構成によれば、簡便に微細なサイズの参照極を、簡便に製作可能である。
(5) The electrochemical cell, wherein the positive reference electrode and / or the negative reference electrode is obtained by electrochemically depositing a reference electrode material on a conductive substrate.
According to the configuration of (5), it is possible to easily manufacture a reference electrode having a fine size.
本発明の電気化学セルは電池、キャパシタ等の内部抵抗を正極、負極、電解液(セパレータ)の各抵抗に、簡便かつ精度良く同時に分離可能であるという効果を奏する。   The electrochemical cell of the present invention has an effect that the internal resistance of a battery, a capacitor or the like can be easily and accurately simultaneously separated into each resistance of a positive electrode, a negative electrode, and an electrolyte (separator).
本発明の電気化学セルの構成の一例を示すものである。An example of the structure of the electrochemical cell of this invention is shown. 図1に示す電気化学セルの断面方向構造を示すものである。2 shows a cross-sectional structure of the electrochemical cell shown in FIG. 本発明の正参照極及び負参照極の位置の一例を示すものである。An example of the position of the positive reference pole of this invention and a negative reference pole is shown. 図3においてA部、B部を矢印方向から見たときの正参照極及び負参照極の位置の一例を示すものである。図4(a)は正極側A部を、図4(b)は負極側B部を矢印方向から見たときの説明図である。FIG. 3 shows an example of the positions of the positive reference electrode and the negative reference electrode when the parts A and B are viewed from the arrow direction. 4A is an explanatory view of the positive electrode side A portion and FIG. 4B is an explanatory view of the negative electrode side B portion viewed from the direction of the arrow. 正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)を説明するものである。The distance (d1) between the positive electrode and the positive reference electrode disposed on the positive electrode surface and the distance (d2) between the negative electrode and the negative reference electrode disposed on the negative electrode surface will be described. 正参照極、負参照極の寸法を説明する図である。It is a figure explaining the dimension of a positive reference pole and a negative reference pole. 本発明実施例1の測定結果を示す図である。It is a figure which shows the measurement result of this invention Example 1. FIG. 本発明実施例1のB点の測定結果を示す図である。It is a figure which shows the measurement result of B point of this invention Example 1. FIG.
本発明の一実施形態について、説明すれば以下の通りである。本発明の電気化学セルは、正極、負極及び少なくとも2つの参照極を有する電気化学セルであって、少なくとも1つの参照極は、正極面上の近傍に配置されている正参照極であり、少なくとも1つの参照極は、負極面上の近傍に配置されている負参照極であり、前記参照極の幅(W)が0.15mm以下、正極と正極面上の近傍に配置された正参照極との距離(d1)及び負極と負極面上の近傍に配置された負参照極との距離(d2)がW以上である。図1は本発明の電気化学セルの構成の一例を示すものであり、図2は図1に示す電気化学セルの断面方向構造を示すものである。本発明の電気化学セルは正極集電体1’上に形成された正極層1よりなる正極、負極集電体2’上に形成された負極層2よりなる負極及び正極、負極間に配置されたセパレータ5、正極面上の近傍に配置された正参照極3、正参照極の電位を取り出すためのリード3’、負極面上の近傍に配置された負参照極4、負参照極の電位を取り出すためのリード4’より構成される。セパレータ5には電解液が含浸されている。正極面上あるいは負極面上の近傍とは正極と負極との間の任意の位置であり、正極面上の近傍に配置された正参照極は正極と距離(d1)、負極面上の近傍に配置された負参照極は負極と距離(d2)をおいて配置されている。正参照極3、負参照極4は各々少なくとも1つは必要であり、複数の正参照極3、複数の負参照極4を用いることもできる。これら構成材料をプラスチック材、アルミラミネート材、金属材等のケース11に入れ密閉型電気化学セルとする、あるいは、電解液が満たされた容器等にこれら構成材料を漬けることにより開放型電気化学セルにする等そのセル形状については任意に選択することが可能である。   An embodiment of the present invention will be described as follows. The electrochemical cell of the present invention is an electrochemical cell having a positive electrode, a negative electrode, and at least two reference electrodes, and at least one reference electrode is a positive reference electrode disposed in the vicinity on the positive electrode surface, and at least One reference electrode is a negative reference electrode disposed in the vicinity on the negative electrode surface, and the width (W) of the reference electrode is 0.15 mm or less, and the positive reference electrode is disposed in the vicinity on the positive electrode and the positive electrode surface. (D1) and the distance (d2) between the negative electrode and the negative reference electrode disposed in the vicinity on the negative electrode surface are W or more. FIG. 1 shows an example of the structure of the electrochemical cell of the present invention, and FIG. 2 shows the cross-sectional structure of the electrochemical cell shown in FIG. The electrochemical cell of the present invention is disposed between a positive electrode made of a positive electrode layer 1 formed on a positive electrode current collector 1 ′, a negative electrode made of a negative electrode layer 2 formed on a negative electrode current collector 2 ′, a positive electrode, and a negative electrode. Separator 5, positive reference electrode 3 disposed near the positive electrode surface, lead 3 ′ for extracting the potential of the positive reference electrode, negative reference electrode 4 disposed near the negative electrode surface, and potential of the negative reference electrode It is comprised from the lead 4 'for taking out. The separator 5 is impregnated with an electrolytic solution. The vicinity on the positive electrode surface or the negative electrode surface is an arbitrary position between the positive electrode and the negative electrode, and the positive reference electrode arranged in the vicinity on the positive electrode surface is at a distance (d1) from the positive electrode and in the vicinity on the negative electrode surface. The arranged negative reference electrode is arranged at a distance (d2) from the negative electrode. At least one of the positive reference electrode 3 and the negative reference electrode 4 is required, and a plurality of positive reference electrodes 3 and a plurality of negative reference electrodes 4 may be used. These constituent materials are put in a case 11 made of plastic material, aluminum laminate material, metal material or the like to form a sealed electrochemical cell, or an open-type electrochemical cell is immersed in a container filled with an electrolytic solution. For example, the cell shape can be arbitrarily selected.
図1において、正極集電体1’及び負極集電体2’には電極層を形成しない部分を設け、この部分を外部端子として用いる構造を示しているが、正極集電体1’及び負極集電体2’に別途外部端子を溶接する、正極集電体1’及び負極集電体2’を、セルケースを兼ねる金属外装体に接着・圧接する等、その集電構造は任意に選択することが可能である。また、正参照極の電位を取り出すためのリード3’、負参照極の電位を取り出すためのリード4’についても、同様に正参照極3、負参照極4と一体とする、別途リードを電気的に接続する等任意の方法で構成することが可能である。   In FIG. 1, the positive electrode current collector 1 ′ and the negative electrode current collector 2 ′ are provided with a portion where no electrode layer is formed and this portion is used as an external terminal. The current collection structure can be selected arbitrarily, such as welding the external terminal separately to the current collector 2 ', and bonding and pressure-contacting the positive electrode current collector 1' and the negative electrode current collector 2 'to the metal exterior that also serves as the cell case. Is possible. Similarly, the lead 3 ′ for extracting the potential of the positive reference electrode and the lead 4 ′ for extracting the potential of the negative reference electrode are also separately integrated with the positive reference electrode 3 and the negative reference electrode 4. It is possible to configure by any method such as connection.
正参照極3、負参照極4は、測定する電気化学系(電解液系)で電位を発生する材料を適宜選択して用いることが可能であり、例えば、リチウム塩を含む有機電解液系であればリチウム金属、リチウム合金等を用いることができる。本発明でいう正参照極3、負参照極4とは、参照極となりうる材料が電解液(電解質)と接している部分を指す。以下、正参照極3、負参照極4としてリチウム金属を用いる場合を例として具体的に説明するが、本発明の参照極の材料がリチウム金属のみに限定されるものではない。参照極の材料がリチウム金属の場合、正参照極3、負参照極4は、例えば、白金、ニッケル、銅、鉄、ステンレス等の金属線の先端に所定寸法のリチウム金属を圧着する、金属線の一部表面にリチウム金属を張り付ける、金属線の一部表面にリチウム金属を電析させる、金属線の一部表面にリチウム金属をコーティングさせる等の方法により製作することが可能である。これらの場合、正参照極3、負参照極4はリチウム金属が存在する部分を指し、リチウム金属が存在しない部分はリード3’、リード4’となる。また、本発明では正参照極3、負参照極4の寸法を規定するが、例えば、金属線の一部表面にリチウム金属を張り付けて正参照極3、負参照極4を製作した場合、リチウム金属が存在する部分の金属線も含めたサイズである。   The positive reference electrode 3 and the negative reference electrode 4 can be used by appropriately selecting a material that generates a potential in the electrochemical system (electrolytic solution system) to be measured. For example, the positive reference electrode 3 and the negative reference electrode 4 are organic electrolytic systems containing lithium salts. If it exists, lithium metal, a lithium alloy, etc. can be used. The positive reference electrode 3 and the negative reference electrode 4 in the present invention refer to a portion where a material that can be a reference electrode is in contact with an electrolyte solution (electrolyte). Hereinafter, the case where lithium metal is used as the positive reference electrode 3 and the negative reference electrode 4 will be specifically described as an example. However, the material of the reference electrode of the present invention is not limited to only lithium metal. When the material of the reference electrode is lithium metal, the positive reference electrode 3 and the negative reference electrode 4 are, for example, metal wires in which lithium metal having a predetermined dimension is crimped to the tip of a metal wire such as platinum, nickel, copper, iron, stainless steel, etc. It is possible to manufacture by a method such as attaching lithium metal to a partial surface of the metal wire, electrodepositing lithium metal on a partial surface of the metal wire, or coating lithium metal on a partial surface of the metal wire. In these cases, the positive reference electrode 3 and the negative reference electrode 4 indicate portions where lithium metal is present, and the portions where lithium metal is not present are the lead 3 ′ and the lead 4 ′. In the present invention, the dimensions of the positive reference electrode 3 and the negative reference electrode 4 are defined. For example, when the positive reference electrode 3 and the negative reference electrode 4 are manufactured by attaching lithium metal to a part of the surface of the metal wire, It is the size including the metal wire where the metal exists.
図3には本発明の正参照極及び負参照極の位置の一例を説明する図面であり、図4は図3においてA部、B部を矢印方向から見た正参照極及び負参照極の位置の一例を説明する図面である。図4(a)及び図(b)中の破線Yで囲った部分がセパレータ5の背面に正極及び負極が存在する範囲である。本発明では、正参照極は正極面上の近傍に、負参照極は負極面上の近傍に配置することにより、各参照極の位置決めを容易に行うことができる。ここで、正参照極3及び負参照極4は、全部が各々正極面上、負極面上にあるように図示されているが、正参照極3及び負参照極4の一部が各々正極面上、負極面上にあってもよい。図3、図4中の破線Xは、正極あるいは負極の電極端面を表しており、正参照極3及び負参照極4の全部が図3、図4に示すように正極あるいは負極の電極端面より内側に配置することがより好ましく、更に、正参照極3及び負参照極4は、正極と負極間の垂直線上に並ばないように配置することが好ましく、この場合、例えば、背景技術に記載の休止法抵抗の「オーム成分」の測定精度をより高めることが可能である。   FIG. 3 is a diagram for explaining an example of the positions of the positive reference electrode and the negative reference electrode of the present invention. FIG. 4 is a diagram of the positive reference electrode and the negative reference electrode viewed from the direction of the arrow A and B in FIG. It is drawing explaining an example of a position. A portion surrounded by a broken line Y in FIGS. 4A and 4B is a range where the positive electrode and the negative electrode exist on the back surface of the separator 5. In the present invention, the reference electrode can be easily positioned by arranging the positive reference electrode in the vicinity on the positive electrode surface and the negative reference electrode in the vicinity on the negative electrode surface. Here, although the positive reference electrode 3 and the negative reference electrode 4 are all shown on the positive electrode surface and the negative electrode surface, the positive reference electrode 3 and a part of the negative reference electrode 4 are respectively positive electrode surfaces. It may be on the negative electrode surface. The broken line X in FIGS. 3 and 4 represents the electrode end face of the positive electrode or the negative electrode, and the positive reference electrode 3 and the negative reference electrode 4 are all from the electrode end face of the positive electrode or the negative electrode as shown in FIGS. More preferably, the positive reference electrode 3 and the negative reference electrode 4 are preferably arranged so as not to be aligned on a vertical line between the positive electrode and the negative electrode. In this case, for example, as described in the background art It is possible to further increase the measurement accuracy of the “ohmic component” of the pause method resistance.
図5は正極と正極面上に配置された正参照極3との距離(d1)及び負極と負極面上に配置された負参照極4との距離(d2)を説明する図であるが、d1、d2は各々正極面(セパレータ5側の電極面)と正参照極の最短距離、負極面(セパレータ5側の電極面)と負参照極の最短距離である。ここで、d1は正参照極3の幅(W)以上、d2は負参照極4の幅(W)以上であり、好ましくは2W以上、更に好ましくは3W以上である。その上限は特には限定しないが10W以下であり、これを超える場合、電気化学セルの内部抵抗が大きくなり、抵抗測定が難しくなる場合がある。また、d1、d2が各参照極の幅未満の場合には、その位置決めが困難になると伴に、各参照極が正負極間の充放電反応を阻害することも生じ易く、例えば、背景技術に記載の休止法抵抗の測定を精度良く実施することが難しくなる。   FIG. 5 is a diagram for explaining the distance (d1) between the positive electrode and the positive reference electrode 3 disposed on the positive electrode surface and the distance (d2) between the negative electrode and the negative reference electrode 4 disposed on the negative electrode surface. d1 and d2 are the shortest distance between the positive electrode surface (electrode surface on the separator 5 side) and the positive reference electrode, and the shortest distance between the negative electrode surface (electrode surface on the separator 5 side) and the negative reference electrode. Here, d1 is equal to or greater than the width (W) of the positive reference electrode 3, d2 is equal to or greater than the width (W) of the negative reference electrode 4, preferably 2W or more, and more preferably 3W or more. Although the upper limit is not specifically limited, it is 10 W or less, and when it exceeds this, the internal resistance of the electrochemical cell increases, and resistance measurement may be difficult. In addition, when d1 and d2 are less than the width of each reference electrode, positioning becomes difficult, and each reference electrode easily inhibits the charge / discharge reaction between the positive and negative electrodes. It becomes difficult to carry out the measurement of the pause method resistance described with high accuracy.
図6は正参照極3、負参照極4の寸法を説明する図である。本発明において正参照極3、負参照極4の形状は特に限定されるものではなく、図6(a)では直方体、図6(b)では円柱を記載し説明するが、通常不定形であり、略直方体、略円柱等様々な形状をとる。正参照極及び負参照極の幅(W)は図6に示すとおりであるが、円柱の場合は直径、不定形の場合のWは各参照極の幅方向の距離の最大値である。本発明において、正参照極及び負参照極の幅(W)は0.15mm以下、好ましくは0.1mm以下、更に好ましくは0.08mm以下であり、参照極製作可能な幅以上であればよい。本発明の参照極の幅は特許文献1に記載されている幅(1mm)に比べ、極度に小さいが、正極面上の近傍あるいは負極面上の近傍に配置する為には、このレベルの幅が必要となる。その理由として、正参照極及び負参照極の幅(W)が上限を超える場合、d1、d2をW以上に大きくとる必要があることから、電気化学セル全体の内部抵抗が大きくなり抵抗測定が難しくなる。また、各参照極が正負極間の充放電反応を阻害することも生じ易く、例えば、背景技術に記載の休止法抵抗の測定を精度良く実施することも難しくなる。また、キャパシタ等の抵抗の小さいデバイスほど、正参照極及び負参照極の幅(W)を小さくする必要があり、例えば、Wが0.05mm以下にすることが必要となることがある。   FIG. 6 is a diagram for explaining the dimensions of the positive reference electrode 3 and the negative reference electrode 4. In the present invention, the shapes of the positive reference electrode 3 and the negative reference electrode 4 are not particularly limited. In FIG. 6 (a), a rectangular parallelepiped is illustrated and described as a cylinder, but it is usually indefinite. Various shapes such as a substantially rectangular parallelepiped and a substantially cylindrical shape are taken. The widths (W) of the positive reference electrode and the negative reference electrode are as shown in FIG. 6, but in the case of a cylinder, W is the maximum value of the distance in the width direction of each reference electrode. In the present invention, the width (W) of the positive reference electrode and the negative reference electrode is 0.15 mm or less, preferably 0.1 mm or less, more preferably 0.08 mm or less, as long as the reference electrode can be manufactured. . The width of the reference electrode of the present invention is extremely small compared to the width (1 mm) described in Patent Document 1, but this level of width is required for placement in the vicinity on the positive electrode surface or in the vicinity on the negative electrode surface. Is required. The reason is that when the width (W) of the positive reference electrode and the negative reference electrode exceeds the upper limit, d1 and d2 must be set to be larger than W. Therefore, the internal resistance of the entire electrochemical cell is increased and resistance measurement is performed. It becomes difficult. In addition, each reference electrode is likely to inhibit the charge / discharge reaction between the positive and negative electrodes, and for example, it becomes difficult to accurately measure the quiescent resistance described in the background art. In addition, it is necessary to reduce the width (W) of the positive reference electrode and the negative reference electrode for a device having a lower resistance such as a capacitor. For example, W may be required to be 0.05 mm or less.
正参照極及び負参照極の厚み(H)は図6に示すとおりであるが、円柱の場合は直径、不定形の場合のWは各参照極の厚み方向の距離の最大値である。本発明において、正参照極及び負参照極の厚み(H)は特に限定するものではなく、正負極の距離等により適宜決定することができるが、0.15mm以下が好ましく、0.1mm以下であれば更に好ましく、参照極の厚み(H)も製作可能であれば、できるだけ薄い方が好ましい。正参照極及び負参照極の厚み(H)がこの範囲にある場合、特に、電解液(セパレータ)の抵抗の分離精度を更に向上することが可能である。   The thicknesses (H) of the positive reference electrode and the negative reference electrode are as shown in FIG. 6, but in the case of a cylinder, W is the maximum value of the distance in the thickness direction of each reference electrode. In the present invention, the thickness (H) of the positive reference electrode and the negative reference electrode is not particularly limited, and can be appropriately determined depending on the distance between the positive electrode and the negative electrode, but is preferably 0.15 mm or less, and 0.1 mm or less. If the thickness (H) of the reference electrode can be manufactured, it is preferable that it is as thin as possible. When the thickness (H) of the positive reference electrode and the negative reference electrode is within this range, it is possible to further improve the separation accuracy of the resistance of the electrolytic solution (separator).
正参照極及び負参照極の長さ(L)は図6に示すとおりであるが、不定形の場合のWは各参照極の長さ方向の距離の最大値である。本発明において、正参照極及び負参照極の長さ(L)は特に限定するものではなく、正負極のサイズ等により適宜決定することができるが、5mm以下が好ましく、3mm以下であれば更に好ましく、前記参照極の長さ(L)も製作可能であれば、できるだけ短い方が好ましい。正参照極及び負参照極の長さ(L)がこの範囲にある場合、例えば、背景技術に記載の休止法抵抗における「平衡成分」の測定精度を更に向上することが可能である。   The lengths (L) of the positive reference electrode and the negative reference electrode are as shown in FIG. 6, but W in the case of an indefinite shape is the maximum value of the distance in the length direction of each reference electrode. In the present invention, the lengths (L) of the positive reference electrode and the negative reference electrode are not particularly limited and can be appropriately determined depending on the size of the positive electrode and the negative electrode, but are preferably 5 mm or less, and more preferably 3 mm or less. Preferably, the length (L) of the reference electrode is preferably as short as possible if it can be manufactured. When the length (L) of the positive reference electrode and the negative reference electrode is in this range, for example, it is possible to further improve the measurement accuracy of the “equilibrium component” in the pause method resistance described in the background art.
正参照極及び負参照極は上述の範囲であれば、各々の寸法やd1、d2の距離が異なっていても問題ないが、可能な限り同じサイズにすることが好ましい。   As long as the positive reference electrode and the negative reference electrode are in the above-mentioned range, there is no problem even if the dimensions and distances of d1 and d2 are different, but it is preferable to make them the same size as much as possible.
上述ごとく本発明における正参照極及び負参照極は、その寸法が小さいことから、その製作が困難な場合がある。このような場合、正参照極及び/あるいは負参照極が導電性基材上に、リチウム金属等の参照極材料を電気化学的に析出させて製作することが可能である。この方法を用いた場合、例えば、参照極の幅(W)が0.08mm以下、参照極の厚み(H)が0.05mm以下、参照極の長さ(L)が0.5mm以下の微細な形状の参照極を容易に製作することができる。例えば、厚さ0.03mmのステンレス板をエッチング加工等の微細加工で幅0.03mmにカットし、先端0.1mmを残し絶縁材料で被覆した導電性基材を準備し、その両面にリチウム金属を5μmの厚さで電気化学的に析出させて製作した参照極は、幅(W)が0.03mm、厚み(H)が0.04mm、長さ(L)が0.1mmと非常に微細なものである。   As described above, the positive reference electrode and the negative reference electrode in the present invention may be difficult to manufacture because of their small dimensions. In such a case, the positive reference electrode and / or the negative reference electrode can be manufactured by electrochemically depositing a reference electrode material such as lithium metal on the conductive substrate. When this method is used, for example, the reference electrode width (W) is 0.08 mm or less, the reference electrode thickness (H) is 0.05 mm or less, and the reference electrode length (L) is 0.5 mm or less. A reference electrode having a simple shape can be easily manufactured. For example, a stainless steel plate having a thickness of 0.03 mm is cut into a width of 0.03 mm by fine processing such as etching, and a conductive base material is prepared which is covered with an insulating material while leaving a tip of 0.1 mm. The reference electrode manufactured by electrochemically depositing 5 μm in thickness is 0.03 mm in width (W), 0.04 mm in thickness (H), and 0.1 mm in length (L). It is a thing.
本発明の電気化学セルは、特に適用範囲が限定されるものではないが、入出力特性、すなわち直流内部抵抗評価が重要とされるリチウムイオン電池、電気二重層キャパシタ、新型リチウム系蓄電デバイス、Ni水素電池等の蓄電デバイスに適用するとその効果は大きい。   The electrochemical cell of the present invention is not particularly limited in scope of application, but the input / output characteristics, that is, the DC internal resistance evaluation is important lithium ion battery, electric double layer capacitor, new lithium-based electricity storage device, Ni The effect is great when applied to an electricity storage device such as a hydrogen battery.
以下に実施例を示し、本発明の特徴とするところをさらに明確化するが、本発明は実施例により何ら限定されるものではない。   EXAMPLES Examples will be shown below to further clarify the features of the present invention, but the present invention is not limited to the examples.
(実施例1)
正極はLiCoO(平均粒径7.4μm)89重量部に導電材であるアセチレンブラック6重量部、バインダーとしてポリフッ化ビニリデン5重量部をN−メチルピロリドン中で混合し、アルミ箔上に塗布・乾燥する事により合剤層を成形し、プレスする事により得た。電極層の厚みは80μmであり、電極密度は2.93g/ccであった。電極の電気伝導度は1.8×10−2S/cmであった。負極は黒鉛化MCMB(平均粒径25μm)93重量部に導電材であるアセチレンブラック2重量部、バインダーとしてポリフッ化ビニリデン5重量部をN−メチルピロリドン中で混合し、銅箔上に塗布・乾燥する事により合剤層を成形し、プレスする事により得た。電極層の厚みは80μmであり、電極密度は1.45g/ccであった。電極の電気伝導度は1.5×10−1S/cmであった。
Example 1
The positive electrode was mixed with 89 parts by weight of LiCoO 2 (average particle size 7.4 μm), 6 parts by weight of acetylene black as a conductive material, and 5 parts by weight of polyvinylidene fluoride as a binder in N-methylpyrrolidone, and applied onto an aluminum foil. The mixture layer was formed by drying and obtained by pressing. The thickness of the electrode layer was 80 μm, and the electrode density was 2.93 g / cc. The electrical conductivity of the electrode was 1.8 × 10 −2 S / cm. For the negative electrode, 93 parts by weight of graphitized MCMB (average particle size 25 μm), 2 parts by weight of acetylene black as a conductive material, and 5 parts by weight of polyvinylidene fluoride as a binder are mixed in N-methylpyrrolidone, and coated on copper foil and dried. This was obtained by molding and pressing the mixture layer. The thickness of the electrode layer was 80 μm, and the electrode density was 1.45 g / cc. Electrical conductivity of the electrodes was 1.5 × 10 -1 S / cm.
図1に示す構造の四極セルを試作した。正極に上記コバルト酸リチウム電極,正極に上記黒鉛電極を用い、電解液としては1モル濃度のLiPF−3EC/7MEC(6フッ化リン酸リチウムをエチレンカーボネート/メチルエチルカーボネート〔重量比で3:7混合〕に溶解)であり,セパレータ5にはガラス繊維の不織布(厚み190μm,気孔率90%)を8枚用いている。正極層1、負極層2のサイズは14mm×20mmであり、図4に示すように正極集電体1’及び負極集電体2’は外部端子として電極層を形成しない部分を設けてある。また、正極層1、負極層2、セパレータ5には電解液が含浸されている。 A quadrupole cell having the structure shown in FIG. The lithium cobaltate electrode is used as the positive electrode, the graphite electrode is used as the positive electrode, and the electrolyte solution is LiPF 6 -3EC / 7MEC (lithium hexafluorophosphate ethylene carbonate / methyl ethyl carbonate [weight ratio 3: The separator 5 is composed of eight glass fiber nonwoven fabrics (thickness 190 μm, porosity 90%). The size of the positive electrode layer 1 and the negative electrode layer 2 is 14 mm × 20 mm. As shown in FIG. 4, the positive electrode current collector 1 ′ and the negative electrode current collector 2 ′ are provided with portions that do not form electrode layers as external terminals. Further, the positive electrode layer 1, the negative electrode layer 2, and the separator 5 are impregnated with an electrolytic solution.
正参照極3、負参照極4は線径0.06mmのステンレス線に厚さ30μmのリチウムを両面から圧着したのち幅方向、長さ方向にカットすることにより、幅(W)を0.1mm、厚み(H)を0.12mm、長さ(L)は2mmとした。正参照極3は正極面上の近傍に、負参照極4は負極面上の近傍に図2の如く、上記セパレータ1枚を介して配置されており、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)は0.19mmである。このように正極と正参照極との距離(d1)及び負極と負参照極との距離(d2)は、セパレータをスペーサーとして参照極を配置するので、より容易にかつ精度良く決めることができる。正参照極3及び負参照極4の全部は図4及び図5に示すように正極、負極の各々の電極端面より0.1mm内側に配置した。   The positive reference electrode 3 and the negative reference electrode 4 have a width (W) of 0.1 mm by crimping 30 μm-thick lithium from both sides to a stainless steel wire with a wire diameter of 0.06 mm and then cutting them in the width and length directions. The thickness (H) was 0.12 mm and the length (L) was 2 mm. As shown in FIG. 2, the positive reference electrode 3 is disposed in the vicinity of the positive electrode surface, and the negative reference electrode 4 is disposed in the vicinity of the negative electrode surface via the one separator, and the positive reference electrode 3 disposed on the positive electrode and the positive electrode surface. The distance (d1) from the reference electrode and the distance (d2) from the negative electrode to the negative reference electrode arranged on the negative electrode surface are 0.19 mm. Thus, the distance (d1) between the positive electrode and the positive reference electrode and the distance (d2) between the negative electrode and the negative reference electrode can be determined more easily and accurately because the reference electrode is disposed using the separator as a spacer. All of the positive reference electrode 3 and the negative reference electrode 4 were arranged 0.1 mm inside the electrode end surfaces of the positive electrode and the negative electrode as shown in FIGS.
得られた電気化学セルを、非特許文献1に記載の電流休止法を用いて測定した。測定条件は4.5mAの電流を12分間印加/60秒休止するサイクルを、充電過程は放電末よりセル電圧(正極−負極間電圧)が4.2Vに達するまで、放電過程はセル電圧が2.5Vに達するまで実施した。この時、正極−負極間電圧(P−Nと記載する)、正極−正参照極電位(P−RPと記載する)、負極−負参照極電位(N−RNと記載する)を計測した。電圧計測には、参照極の消耗を防ぐために入力抵抗10MΩ以上の計測機を用いるのが好ましく、本実施例では入力抵抗10GΩのエレクトロメータを使用した。   The obtained electrochemical cell was measured using the current pause method described in Non-Patent Document 1. The measurement condition is a cycle in which a current of 4.5 mA is applied for 12 minutes / pause for 60 seconds. In the charging process, the cell voltage is 2 until the cell voltage (positive electrode-negative electrode voltage) reaches 4.2 V from the end of the discharge. It carried out until it reached 5V. At this time, the positive electrode-negative electrode voltage (described as P-N), the positive electrode-positive reference electrode potential (described as P-RP), and the negative electrode-negative reference electrode potential (described as N-RN) were measured. For voltage measurement, it is preferable to use a measuring instrument with an input resistance of 10 MΩ or more in order to prevent the consumption of the reference electrode. In this embodiment, an electrometer with an input resistance of 10 GΩ was used.
休止法抵抗は休止時の電圧変化から、休止直前の電圧と60秒休止後の電圧差を印加電流である4.5mAで割ることによりを求めた。また、非特許文献1に記載されているとおり、0から1秒までの電圧変化から算出される抵抗(休止法抵抗のオーム成分と呼ぶ)、1秒から60秒までの電圧変化から算出される抵抗(休止法抵抗の平衡成分と呼ぶ)についても同様に計算した。   The resting resistance was obtained by dividing the voltage difference immediately before resting from the voltage immediately before resting and the voltage difference after resting for 60 seconds by the applied current of 4.5 mA. Further, as described in Non-Patent Document 1, a resistance calculated from a voltage change from 0 to 1 second (referred to as an ohmic component of a pause method resistance) is calculated from a voltage change from 1 second to 60 seconds. The resistance (referred to as the equilibrium component of the quiescent resistance) was similarly calculated.
図7に充電過程、放電過程の電圧カーブを示す。このセルの放電容量は7.3mAhであった。図7には3本の充電あるいは放電カーブがある。2.5V〜4.2V間の電圧カーブは正極−負極間電圧(P−N)であり、その上にある4V近辺の電圧カーブが正極−正参照極間電位(P−RP)電位、0V〜1V間の電圧カーブは負極−負参照極間電位(N−RN)である。図中、各カーブにおける角上の部分が休止点である。以下、放電第1休止点の結果を用いて本発明を説明する。   FIG. 7 shows voltage curves of the charging process and discharging process. The discharge capacity of this cell was 7.3 mAh. In FIG. 7, there are three charge or discharge curves. The voltage curve between 2.5V and 4.2V is the voltage between the positive electrode and the negative electrode (PN), and the voltage curve near 4V above it is the potential between the positive electrode and the positive reference electrode (P-RP), 0V The voltage curve between ˜1V is the negative electrode-negative reference electrode potential (N-RN). In the figure, the portion on the corner of each curve is the rest point. Hereinafter, the present invention will be described using the result of the first discharge rest point.
図8に放電第1休止点(図7中B点)の拡大図を示す。P−Nの休止時の電圧変化(図8a)の休止直前の電圧と60秒休止後の電圧差を印加電流である4.5mAで割ることにより、セル休止法抵抗を求めた。セル休止法抵抗は17.0Ωであった。また、0から1秒までの電圧変化から算出される抵抗(休止法抵抗のオーム成分)、1秒から60秒までの電圧変化から算出される抵抗(休止法抵抗の平衡成分)についても同様に計算した。セルの休止法抵抗のオーム成分は12.5Ω、平衡成分は4.5Ωである。非特許文献1によれば、P−RPの休止時の電圧変化(図8b)から正極休止法抵抗、N−RNの休止時の電圧変化(図8c)から負極休止法抵抗を分離できることが示されている。これに従い、セル休止法抵抗と同様に計算し、正極休止法抵抗、負極休止法抵抗を算出した。正極休止法抵抗は4.2Ω、そのオーム成分は2.7Ω、平衡成分は1.5Ω、負極休止法抵抗は7.7Ω、オーム成分は4.4Ω、平衡成分は3.3Ωであった。   FIG. 8 shows an enlarged view of the first discharge rest point (point B in FIG. 7). The cell pause method resistance was obtained by dividing the voltage change immediately before the pause of the voltage change during the pause of PN (FIG. 8a) and the voltage difference after the 60 second pause by the applied current of 4.5 mA. The cell pause method resistance was 17.0Ω. The same applies to the resistance calculated from the voltage change from 0 to 1 second (ohmic component of the pause method resistance) and the resistance calculated from the voltage change from 1 second to 60 seconds (the equilibrium component of the pause method resistance). Calculated. The ohmic component of the quiescent resistance of the cell is 12.5Ω and the equilibrium component is 4.5Ω. According to Non-Patent Document 1, it is shown that the positive electrode pause method resistance can be separated from the voltage change during P-RP pause (FIG. 8b), and the negative electrode pause method resistance can be separated from the voltage change during N-RN pause (FIG. 8c). Has been. According to this, the calculation was made in the same manner as the cell pause method resistance, and the positive electrode pause method resistance and the negative electrode pause method resistance were calculated. The positive electrode pause method resistance was 4.2Ω, its ohmic component was 2.7Ω, the equilibrium component was 1.5Ω, the negative electrode pause method resistance was 7.7Ω, the ohmic component was 4.4Ω, and the equilibrium component was 3.3Ω.
また、セル休止法抵抗と、分離した正極休止法抵抗、負極休止法抵抗の差分からセパレータ(電解液を含む)抵抗(図2中における正参照極3と負参照極4にあるセパレータ6枚分の抵抗)を求めた。セル休止法抵抗(17.0Ω)から正極休止法抵抗(4.2Ω)と負極休止法抵抗(7.7Ω)を引くと5.1Ωであり、これがセパレータ6枚分の休止法抵抗であることから、セパレータ(電解液を含む)1枚あたり0.9Ωである。また、正極休止法抵抗、負極休止法抵抗には各々セパレータ(電解液を含む)1枚分の抵抗が含まれることから、上記値からセパレータ(電解液を含む)1枚を引くことにより精度良く正極抵抗、負極抵抗を分離可能である。   Further, the separator (including the electrolyte) resistance (including 6 separators in the positive reference electrode 3 and the negative reference electrode 4 in FIG. 2) is calculated from the difference between the cell pause method resistance, the separated positive electrode pause method resistance, and the negative electrode pause method resistance. Resistance). Subtracting the positive electrode pause method resistance (4.2Ω) and the negative electrode pause method resistance (7.7Ω) from the cell pause method resistance (17.0Ω) is 5.1Ω, and this is the pause method resistance for six separators. To 0.9Ω per separator (including electrolyte). In addition, each of the positive electrode pause method resistance and the negative electrode pause method resistance includes the resistance of one separator (including electrolytic solution), and therefore, by accurately subtracting one separator (including electrolytic solution) from the above value, The positive electrode resistance and the negative electrode resistance can be separated.
上記実施例の如く、本発明の電気化学セルを用いることにより正極、負極、電解液(セパレータ)の各抵抗を精度良く同時に分離可能である。   Like the said Example, each resistance of a positive electrode, a negative electrode, and electrolyte solution (separator) is separable simultaneously with sufficient precision by using the electrochemical cell of this invention.
(実施例2)
実施例1において参照極を次のように変更する以外は実施例1と同様に四極セルを試作した。正参照極3、負参照極4は幅0.03mm、厚さ0.03mmのステンレス板にその両面からリチウムをセル内で電気化学的に析出させることにより得た。参照極の長さは、リチウムを電析させる部分以外は変性ポリエチレンフィルムによりマスクすることにより決めた。正参照極3、負参照極4は伴に幅(W)を0.03mm、厚み(H)を0.04mm、長さ(L)は0.2mmとした。正参照極3は正極面上の近傍に、負参照極4は負極面上の近傍に図2の如く、上記セパレータ1枚を介して配置されており、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)は0.19mmである。正参照極3及び負参照極4の全部は図4及び図5に示すように正極、負極の各々の電極端面より0.1mm内側に配置した。
(Example 2)
A quadrupole cell was prototyped in the same manner as in Example 1 except that the reference electrode in Example 1 was changed as follows. The positive reference electrode 3 and the negative reference electrode 4 were obtained by electrochemically depositing lithium from both sides of a stainless plate having a width of 0.03 mm and a thickness of 0.03 mm in the cell. The length of the reference electrode was determined by masking with a modified polyethylene film except for the portion where lithium was electrodeposited. The positive reference electrode 3 and the negative reference electrode 4 have a width (W) of 0.03 mm, a thickness (H) of 0.04 mm, and a length (L) of 0.2 mm. As shown in FIG. 2, the positive reference electrode 3 is disposed in the vicinity of the positive electrode surface, and the negative reference electrode 4 is disposed in the vicinity of the negative electrode surface via the one separator, and the positive reference electrode 3 disposed on the positive electrode and the positive electrode surface. The distance (d1) from the reference electrode and the distance (d2) from the negative electrode to the negative reference electrode arranged on the negative electrode surface are 0.19 mm. As shown in FIGS. 4 and 5, the positive reference electrode 3 and the negative reference electrode 4 were all arranged 0.1 mm inside from the electrode end surfaces of the positive electrode and the negative electrode.
実施例1と同様に電流休止法で抵抗を評価した。セル休止法抵抗は17.3Ω、セルの休止法抵抗のオーム成分は12.4Ω、平衡成分は4.9Ωとなり、正極休止法抵抗は4.4Ω、そのオーム成分は2.8Ω、平衡成分は1.6Ω、負極休止法抵抗は7.5Ω、オーム成分は4.1Ω、平衡成分は3.4Ωであり、セパレータ(電解液を含む)抵抗は1枚あたり0.9Ωであった。実施例1と同様の結果が得られた。   The resistance was evaluated by the current pause method as in Example 1. The cell pause method resistance is 17.3Ω, the ohmic component of the cell pause method resistance is 12.4Ω, the equilibrium component is 4.9Ω, the positive electrode pause method resistance is 4.4Ω, the ohmic component is 2.8Ω, and the equilibrium component is The resistance of the negative electrode resting method was 7.5Ω, the ohmic component was 4.1Ω, the equilibrium component was 3.4Ω, and the separator (including electrolyte) resistance was 0.9Ω. The same result as in Example 1 was obtained.
(比較例1)
実施例1において参照極を次のように変更する以外は実施例1と同様に四極セルを試作した。正参照極3、負参照極4は線径0.06mmのステンレス線に厚さ50μmのリチウムを両面から圧着した後、幅方向、長さ方向にカットすることにより、幅(W)を0.2mm、厚み(H)を0.16mm、長さ(L)は2mmとした。正参照極3は正極面上の近傍に、負参照極4は負極面上の近傍に図2の如く、上記セパレータ1枚を介して配置されており、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)は0.19mmである。正参照極3及び負参照極4の全部は図4及び図5に示すように正極、負極の各々の電極端面より0.1mm内側に配置した。
(Comparative Example 1)
A quadrupole cell was prototyped in the same manner as in Example 1 except that the reference electrode in Example 1 was changed as follows. The positive reference electrode 3 and the negative reference electrode 4 are bonded to a stainless steel wire having a wire diameter of 0.06 mm with a thickness of 50 μm from both sides, and then cut in the width direction and the length direction so that the width (W) is reduced to 0.0. The thickness (H) was 0.16 mm and the length (L) was 2 mm. As shown in FIG. 2, the positive reference electrode 3 is disposed in the vicinity of the positive electrode surface, and the negative reference electrode 4 is disposed in the vicinity of the negative electrode surface via the one separator, and the positive reference electrode 3 disposed on the positive electrode and the positive electrode surface. The distance (d1) from the reference electrode and the distance (d2) from the negative electrode to the negative reference electrode arranged on the negative electrode surface are 0.19 mm. All of the positive reference electrode 3 and the negative reference electrode 4 were arranged 0.1 mm inside the electrode end surfaces of the positive electrode and the negative electrode as shown in FIGS.
実施例1と同様に電流休止法で抵抗を評価した。セル休止法抵抗は17.7Ω、セルの休止法抵抗のオーム成分は12.9Ω、平衡成分は4.8Ωとなり、実施例1、実施例2と同様の結果が得られた。しかし、分離した正極休止法抵抗は5.1Ω、そのオーム成分は2.9Ω、平衡成分は2.2Ω、負極休止法抵抗は6.7Ω、オーム成分は4.1Ω、平衡成分は2.6Ωであった。また、セパレータ(電解液を含む)抵抗は1枚あたり1.0Ωであった。分離した平衡成分が、特に、実施例1、実施例2の値に対しずれる結果となった。このように正参照極3、負参照極4の幅(W)が0.15mm以上で、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)はW以下の場合、正極、負極、電解液(セパレータ)の各抵抗を精度良く同時に分離することが難しくなる。   The resistance was evaluated by the current pause method as in Example 1. The cell pause method resistance was 17.7Ω, the ohmic component of the cell pause method resistance was 12.9Ω, and the equilibrium component was 4.8Ω, and the same results as in Example 1 and Example 2 were obtained. However, the separated positive electrode pause method resistance is 5.1Ω, its ohmic component is 2.9Ω, the equilibrium component is 2.2Ω, the negative electrode pause method resistance is 6.7Ω, the ohmic component is 4.1Ω, and the equilibrium component is 2.6Ω. Met. Further, the resistance of the separator (including the electrolytic solution) was 1.0Ω per sheet. In particular, the separated equilibrium components were shifted from the values of Example 1 and Example 2. Thus, the width (W) of the positive reference electrode 3 and the negative reference electrode 4 is 0.15 mm or more, and the distance (d1) between the positive electrode and the positive reference electrode arranged on the positive electrode surface and the negative electrode and the negative electrode surface are arranged. When the distance (d2) from the negative reference electrode is W or less, it becomes difficult to accurately separate the resistances of the positive electrode, the negative electrode, and the electrolytic solution (separator) at the same time.
ハイブリッド電気自動車、瞬時停電バックアップ等の大電流負荷用途に向けた、最先端蓄電デバイスであるリチウムイオン電池、リチウムイオンキャパシタ、電気二重層キャパシタ等の内部抵抗に関し、正極、負極、電解液(セパレータ)の各抵抗を簡便にかつ精度良く同時に分離可能な電気化学セルを提供する。本発明の電気化学セルを用いることにより、大電流負荷用途蓄電デバイスにおいて重要な抵抗をより詳細に解析できると伴に、正極、負極、電解液(セパレータ)の各抵抗を基準とした新たな充放電制御等も可能となる。   For internal resistance of lithium-ion batteries, lithium-ion capacitors, electric double-layer capacitors, etc., which are state-of-the-art storage devices for high-current load applications such as hybrid electric vehicles and instantaneous power outages, positive electrodes, negative electrodes, electrolytes (separators) It is possible to provide an electrochemical cell capable of easily and accurately simultaneously separating the resistors. By using the electrochemical cell of the present invention, it is possible to analyze in more detail important resistances in an electricity storage device for large current loads, and at the same time, new charges based on the resistances of the positive electrode, negative electrode, and electrolyte (separator) are used. Discharge control and the like are also possible.
1 正極層
1’ 正極集電体
2 負極層
2’ 負極集電体
3 正参照極
3’ 正参照極リード
4 負参照極
4’ 負参照極リード
5 セパレータ(電解液を含む)
11 ケース
DESCRIPTION OF SYMBOLS 1 Positive electrode layer 1 'Positive electrode collector 2 Negative electrode layer 2' Negative electrode collector 3 Positive reference pole 3 'Positive reference pole lead 4 Negative reference pole 4' Negative reference pole lead 5 Separator (including electrolyte)
11 cases

Claims (5)

  1. 正極、負極及び少なくとも2つの参照極を有する電気化学セルであって、少なくとも1つの参照極は、正極面上の近傍に配置されている正参照極であり、少なくとも1つの参照極は、負極面上の近傍に配置されている負参照極であり、前記参照極の幅(W)が0.15mm以下、正極と正極面上に配置された正参照極との距離(d1)及び負極と負極面上に配置された負参照極との距離(d2)がW以上であることを特徴とする電気化学セル。   An electrochemical cell having a positive electrode, a negative electrode and at least two reference electrodes, wherein at least one reference electrode is a positive reference electrode disposed in the vicinity on the positive electrode surface, and at least one reference electrode is a negative electrode surface A negative reference electrode disposed in the vicinity of the upper electrode, the width (W) of the reference electrode being 0.15 mm or less, a distance (d1) between the positive electrode and the positive reference electrode disposed on the positive electrode surface, and the negative electrode and the negative electrode An electrochemical cell, wherein a distance (d2) from a negative reference electrode disposed on a surface is W or more.
  2. 前記電気化学セルにおいて参照極の厚み(H)が0.15mm以下であることを特徴とする請求項1に記載の電気化学セル。   The electrochemical cell according to claim 1, wherein a thickness (H) of a reference electrode in the electrochemical cell is 0.15 mm or less.
  3. 前記電気化学セルにおいて正参照極及び負参照極の全部が正極あるいは負極の電極端面より内側に配置されることを特徴とする請求項1または請求項2に記載の電気化学セル。   3. The electrochemical cell according to claim 1, wherein all of the positive reference electrode and the negative reference electrode are disposed inside the positive or negative electrode end face in the electrochemical cell.
  4. 前記電気化学セルにおいて参照極の長さ(L)が5mm以下であることを特徴とする請求項1から請求項3のいずれかに記載の電気化学セル。   The electrochemical cell according to any one of claims 1 to 3, wherein a length (L) of a reference electrode in the electrochemical cell is 5 mm or less.
  5. 前記電気化学セルにおいて、正参照極及び/又は負参照極が導電性基材上に参照極材料を電気化学的に析出させたものであることを特徴とする請求項1から請求項4のいずれかに記載の電気化学セル。
    5. The electrochemical cell according to claim 1, wherein the positive reference electrode and / or the negative reference electrode is obtained by electrochemically depositing a reference electrode material on a conductive substrate. An electrochemical cell according to claim 1.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120027926A1 (en) * 2010-07-30 2012-02-02 Honjo Metal Co., Ltd. Reference electrode, its manufacturing method, and an electrochemical cell
JP2012049280A (en) * 2010-08-26 2012-03-08 Daihatsu Motor Co Ltd Electrochemical cell
JP2013191532A (en) * 2012-02-14 2013-09-26 Nippon Soken Inc Lithium ion secondary battery and manufacturing method of the same
WO2015049778A1 (en) * 2013-10-04 2015-04-09 株式会社日立製作所 Lithium ion secondary battery, lithium ion secondary battery system, method for detecting potential in lithium ion secondary battery, and method for controlling lithium ion secondary battery
US20150276884A1 (en) * 2014-03-31 2015-10-01 Hitachi, Ltd. Lithium-ion secondary battery system and status diagnostic method of lithium-ion secondary battery
JP2016143452A (en) * 2015-01-29 2016-08-08 日産自動車株式会社 Lithium ion secondary battery

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005019116A (en) * 2003-06-25 2005-01-20 Kri Inc Electrochemical cell
JP2006179329A (en) * 2004-12-22 2006-07-06 Toyota Motor Corp Electrochemical cell, evaluation device of electrochemical cell, evaluation method of electrochemical cell, and control method of electrochemical cell
JP2007193986A (en) * 2006-01-17 2007-08-02 Nissan Motor Co Ltd Nonaqueous electrolyte secondary battery and its using method
JP2010086873A (en) * 2008-10-01 2010-04-15 Nissan Motor Co Ltd Battery, and method and device for estimating electrode potential of battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005019116A (en) * 2003-06-25 2005-01-20 Kri Inc Electrochemical cell
JP2006179329A (en) * 2004-12-22 2006-07-06 Toyota Motor Corp Electrochemical cell, evaluation device of electrochemical cell, evaluation method of electrochemical cell, and control method of electrochemical cell
JP2007193986A (en) * 2006-01-17 2007-08-02 Nissan Motor Co Ltd Nonaqueous electrolyte secondary battery and its using method
JP2010086873A (en) * 2008-10-01 2010-04-15 Nissan Motor Co Ltd Battery, and method and device for estimating electrode potential of battery

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120027926A1 (en) * 2010-07-30 2012-02-02 Honjo Metal Co., Ltd. Reference electrode, its manufacturing method, and an electrochemical cell
JP2012033365A (en) * 2010-07-30 2012-02-16 National Institute Of Advanced Industrial & Technology Reference electrode, manufacturing method thereof, and electrochemical cell
JP2012049280A (en) * 2010-08-26 2012-03-08 Daihatsu Motor Co Ltd Electrochemical cell
JP2013191532A (en) * 2012-02-14 2013-09-26 Nippon Soken Inc Lithium ion secondary battery and manufacturing method of the same
WO2015049778A1 (en) * 2013-10-04 2015-04-09 株式会社日立製作所 Lithium ion secondary battery, lithium ion secondary battery system, method for detecting potential in lithium ion secondary battery, and method for controlling lithium ion secondary battery
US20150276884A1 (en) * 2014-03-31 2015-10-01 Hitachi, Ltd. Lithium-ion secondary battery system and status diagnostic method of lithium-ion secondary battery
JP2016143452A (en) * 2015-01-29 2016-08-08 日産自動車株式会社 Lithium ion secondary battery

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