Secondary battery, electrical apparatus, and application of silicate multi-metal salt

A secondary battery, comprising a positive electrode plate, a negative electrode plate, a separator, and an electrolytic solution, wherein the separator is located between the positive electrode plate and the negative electrode plate, the positive electrode plate comprises a positive electrode active material layer, and the negative electrode plate comprises a negative electrode active material layer;

• at least one of the positive electrode active material layer and the negative electrode active material layer comprises a silicate multi-metal salt;
• and
• when the positive electrode active material layer comprises the silicate multi-metal salt, the positive electrode active material layer comprises a positive electrode active substance and the silicate multi-metal salt;
• when the negative electrode active material layer comprises the silicate multi-metal salt, the negative electrode active material layer comprises a negative electrode active substance and the silicate multi-metal salt, where the negative electrode active substance comprises one or more of artificial graphite, natural graphite, soft carbon, hard carbon, or a silicon-based material, and the silicon-based material is selected from one or more of monomeric silicon, a silicon oxide, a silicon-carbon complex, a silicon nitrogen complex, or a silicon alloy;
• and
• a chemical formula of the silicate multi-metal salt is at least one selected from YSi2Z1Z2O8 and X1X2Si2Z1Z2O8,
• where
• Y is selected from second main group elements;
• X1 and X2 are each independently selected from first main group elements;
• and
• Z1 and Z2 are each selected from third main group elements.