POSITIVE ELECTRODE AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY HAVING THE SAME

• Main Authors: TSUJIKO AKIRA, SUZUKI SHINYA
• Format: Patent
• Language: English; Japanese
• Published: 14.10.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide a positive electrode with a positive electrode active material layer containing a lithium composite oxide having a high Ni content and a surfactant, the positive electrode being superior in the impregnating ability of a nonaqueous electrolyte solution into the positive electrode active material layer and being arranged so that generation of gas under a high-voltage condition can be suppressed.SOLUTION: A positive electrode herein disclosed comprises: a positive electrode collector; and a positive electrode active material layer supported on the positive electrode collector. The positive electrode active material layer contains a positive electrode active material and a surfactant. The positive electrode active material contains a lithium composite oxide in which the content of nickel to metal atoms other than lithium is 70 mol% or more. The positive electrode active material layer has a multi-layer structure including two or more layers which are different in the mass percentage of the surfactant to a total mass of the positive electrode active material and the surfactant. In one of layers included in the multi-layer structure, which is larger in the mass percentage of the surfactant, the mass percentage of the surfactant is 1.0 mass% or more and 10 mass% or less.SELECTED DRAWING: Figure 1 【課題】Ｎｉ含有量の高いリチウム複合酸化物と界面活性剤とを含有する正極活物質層を備える正極であって、正極活物質層への非水電解液の含浸性に優れ、かつ高電圧下でのガス発生が抑制された正極を提供する。【解決手段】ここに開示される正極は、正極集電体と、前記正極集電体上に支持された正極活物質層とを備える。前記正極活物質層は、正極活物質と、界面活性剤と、を含有する。前記正極活物質は、リチウム以外の金属原子に対するニッケルの含有量が７０モル％以上であるリチウム複合酸化物を含む。前記正極活物質層は、前記正極活物質と前記界面活性剤との合計に対する前記界面活性剤の質量割合が異なる２以上の層を含む複層構造を有する。前記複層構造が含む層のうちの前記界面活性剤の質量割合が大きい層における、前記界面活性剤の前記質量割合が、１．０質量％以上１０質量％以下である。【選択図】図１