POSITIVE ELECTRODE AND LITHIUM ION SECONDARY BATTERY

• Main Authors: SHIMIZU CHIEKO, GOTO SHOTA, OKANO YASUHISA
• Format: Patent
• Language: English; Japanese
• Published: 01.11.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide: a positive electrode which can be used for a lithium ion secondary battery and is superior in output characteristic; and a lithium ion secondary battery having the positive electrode.SOLUTION: A positive electrode according to an embodiment of the present invention comprises: a current collector; and a positive electrode active material layer coated over at least one face of the current collector. The positive electrode active material layer has: a first region of which the density is lower than an average density; and a second region of which the density is higher than the average density. The density of the first region is a value which is 1% or more lower than the average density of the positive electrode active material layer and equal to or larger than a value 30% lower than the average density of the positive electrode active material layer. The density of the second region is a value 1% or more higher than the average density of the positive electrode active material layer and equal to or smaller than a value 37% higher than the average density of the positive electrode active material layer.SELECTED DRAWING: Figure 2 【課題】出力特性に優れたリチウムイオン二次電池に用いることができる正極、及び、この正極を有するリチウムイオン二次電池を提供することを目的とする。【解決手段】本発明の一態様にかかる正極は、集電体と、前記集電体の少なくとも一面に被覆された正極活物質層と、を備え、前記正極活物質層は、平均密度より密度が低い第１領域と、平均密度より密度が高い第２領域と、を有し、前記第１領域の密度は、前記正極活物質層の平均密度より１％以上低く、前記正極活物質層の平均密度より３０％低い値以上であり、前記第２領域の密度は、前記正極活物質層の平均密度より１％以上高く、前記正極活物質層の平均密度より３７％高い値以下である。【選択図】図２