ALL-SOLID BATTERY

• Main Authors: MIZUNO YOSHIFUMI, TAKAICHI SATORU
• Format: Patent
• Language: English; Japanese
• Published: 06.05.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide means capable of suppressing the growth of metallic lithium dendrite at the outer peripheral edge of a negative electrode active material layer even in an all-solid battery having a laminated configuration where a positive electrode active material layer, a solid electrolyte layer and the negative electrode active material layer are laminated in this order.SOLUTION: An all-solid battery includes a power generation element including: a positive electrode; a negative electrode in which a negative electrode active material layer containing a negative electrode active material that contains metallic lithium or a lithium-containing alloy is disposed; and a solid electrolyte layer interposed between the positive and negative electrodes and containing a sulfide solid electrolyte. There is provided a dendrite suppression region in at least part of the outer peripheral edge of the solid electrolyte layer. On this occasion, the composition of the dendrite suppression region contains lithium (Li), phosphorous (P), sulfur (S) and oxygen (O), the atomic ratio (O/S ratio) of an oxygen (O) atom to a sulfur (S) atom is 0.4 or less or 0.8 or more, and the thickness of the region in a lamination direction is 1 μm or more.SELECTED DRAWING: Figure 2 【課題】正極活物質層、固体電解質層および負極活物質層がこの順に積層されてなる積層型の構成を有する全固体電池においても、負極活物質層の外周端部における金属リチウムのデンドライトの成長を抑制することを可能とする手段を提供する。【解決手段】正極と、金属リチウムまたはリチウム含有合金を含む負極活物質を含有する負極活物質層が配置された負極と、これらの間に介在し、硫化物固体電解質を含む固体電解質層とを有する発電要素を備える全固体電池において、前記固体電解質層の外周縁部の少なくとも一部にデンドライト抑制領域を設ける。この際、当該デンドライト抑制領域の組成を、リチウム（Ｌｉ）、リン（Ｐ）、硫黄（Ｓ）および酸素（Ｏ）を含有し、硫黄（Ｓ）原子に対する酸素（Ｏ）原子の原子比率（Ｏ／Ｓ比）が０．４以下または０．８以上とし、かつ、当該領域の積層方向の厚みを１μｍ以上とする。【選択図】図２