ACTIVE MATERIAL

• Main Authors: TAKAHASHI TSUKASA, MITSUMOTO TETSUYA, KAI TAKUYA, HORIUCHI NAOHIRO
• Format: Patent
• Language: English; Japanese
• Published: 20.05.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide an active material capable of maintaining contact between the active material and a solid electrolyte.SOLUTION: An active material has a composition represented by MxSiy (x and y satisfy 0≤x/y≤7.0, M is one kind or two or more kinds of metalloid elements other than Si and metal elements). An initial charge curve indicating the relation between a capacity Q and a voltage V under initial charging on a solid-state battery having metallic lithium as a counter electrode for the active material is measured. The initial charge curve is differentiated with the voltage V to obtain a charge differential curve. When the charge differential curve is divided into a first peak curve having a peak top at 0.07 V ± 0.05 V, a second peak curve having a peak top at 0.20 V ± 0.03 V, and a third peak curve having a peak top in a range from 0.24 V to 0.6 V in terms of lithium reference potential, the ratio of the sum of the area S2 of the second peak curve and the area S3 of the third peak curve to the area S1 of the first peak curve is 0.10 or more.SELECTED DRAWING: Figure 1 【課題】活物質と固体電解質との接触を維持することが可能な活物質を提供すること。【解決手段】ＭｘＳｉｙ（ｘ及びｙは０≦ｘ／ｙ≦７．０であり、Ｍは、Ｓｉ以外の半金属元素及び金属元素のうちの一種又は二種以上である。）で表される組成を有する活物質に対して金属リチウムを対極とした固体電池の初回充電時の容量Ｑと電圧Ｖとの関係である初回充電曲線を測定し、初回充電曲線を電圧Ｖで微分して充電微分曲線を求め、該充電微分曲線を、リチウム基準電位で０．０７Ｖ±０．０５Ｖにピークトップを有する第１ピーク曲線と、０．２０Ｖ±０．０３Ｖにピークトップを有する第２ピーク曲線と、０．２４Ｖから０．６Ｖまでの範囲にピークトップを有する第３ピーク曲線とにピーク分離したとき、第１ピーク曲線の面積Ｓ１に対する、第２ピーク曲線の面積Ｓ２と第３ピーク曲線の面積Ｓ３との和の比率が０．１０以上である、活物質。【選択図】図１