NEGATIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

A negative electrode active material for nonaqueous secondary batteries containing a silicon solid solution. The silicon solid solution has one or more than one of a group 3 semimetal or metal element, a group 4 semimetal or metal element except silicon, and a group 5 nonmetal or semimetal element incorporated in silicon. The solid solution shows an XRD pattern in which the position of the XRD peak of the solid solution corresponding to the XRD peak position assigned to the (422) plane of silicon shifts to the smaller or greater angle side relative to the position of the XRD peak assigned to the (422) plane of silicon peak by 0.1° to 1°. The solid solution has a lattice strain of 0.01% to 1% as determined by XRD.