Solid electrolyte and all-solid-state battery including the same
The present disclosure relates to a solid electrolyte and an all-solid-state battery including the same. Specifically, provided are an oxide of a specific component system as a solid electrolyte (first solid electrolyte) and a solid electrolyte (second solid electrolyte) further including an oxide or salt of another component system as a second component while including the oxide of the specific component system as a first component.
1 . A solid electrolyte comprising Li, Si, B, Zr, and P, wherein
the solid electrolyte is represented by Chemical Formula 1:
a (Li 2 O)· b (SiO 2 )· c (B 2 O 3 )· d (P 2 O 5 )· e (ZrO 2 ) [Chemical Formula 1]
wherein, in Chemical Formula 1,
a to e are real numbers representing mole fractions, 40≤a≤60, 0<b≤30, 0<c≤60, 0<d≤60, and 0<e≤50, and
the solid electrolyte has a Li 3 PO 4 crystal phase having a size of greater than or equal to about 3 nm and less than or equal to about 10 nm in an amorphous structure.
2 . The solid electrolyte of claim 1 , wherein
based on 100 mol % of the total amount of Li, Si, B, Zr, and P, in the solid electrolyte, Li is included in an amount of greater than or equal to about 40 mol % and less than or equal to about 80 mol %, Si is included in an amount of greater than about 0 mol % and less than or equal to about 30 mol %, B is included in an amount of greater than about 0 mol % and less than or equal to about 60 mol %, Zr is included in an amount of greater than about 0 mol % and less than or equal to about 50 mol %, and P is included in an amount of greater than about 0 mol % and less than or equal to about 60 mol %.
3 . The solid electrolyte of claim 1 , wherein
a mole fraction of Li/(Si+B+Zr) in the solid electrolyte is about 0.5 to about 5.
4 . The solid electrolyte of claim 1 , wherein a+b+c+d+e=100.
5 . The solid electrolyte of claim 1 , wherein
a softening point of the solid electrolyte is greater than or equal to about 500° C. and less than or equal to about 550° C.
6 . The solid electrolyte of claim 1 , wherein
the solid electrolyte has an ionic conductivity of greater than or equal to about 1.0×10 −7 S/cm.
7 . An all-solid-state battery, comprising
a body including a solid electrolyte layer and a positive electrode layer and a negative electrode layer alternately stacked with the solid electrolyte layer disposed therebetween; and
a first external electrode disposed on one side of the body and a second external electrode disposed on another side of the body, wherein the solid electrolyte layer includes the solid electrolyte of claim 1 .
8 . The all-solid-state battery of claim 7 , wherein
the positive electrode layer and the negative electrode layer each include a current collecting layer and an electrode active material layer on the current collecting layer;
the current collecting layer and the electrode active material layer each include the solid electrolyte and a carbon-based conductive material; and
the electrode active material layer further includes an electrode active material.