Secondary battery, composite electrolyte, battery pack, and vehicle

Abstract

According to one embodiment, a composite electrolyte includes lithium-containing oxide particles and an electrolytic composition. The electrolytic composition includes lithium ions, an organic solvent and a polymer. A content of the lithium-containing oxide particles in the composite electrolyte falls within a range of from 90% by weight to 98% by weight. A specific surface area of the lithium-containing oxide particles falls within a range of 10 m2/g to 500 m2/g and is measured by a BET adsorption method using N2.

What is claimed is: 
     
         1 . A secondary battery comprising:
 a positive electrode active material-containing layer;   a negative electrode active material-containing layer; and   a composite electrolyte provided between the positive electrode active material-containing layer and the negative electrode active material-containing layer, wherein:   the composite electrolyte comprises lithium-containing oxide particles and an electrolytic composition which comprises lithium ions, an organic solvent and a polymer, and a content of the lithium-containing oxide particles in the composite electrolyte falls within a range of from 90% by weight to 98% by weight and a specific surface area of the lithium-containing oxide particles falls within a range of 10 m 2 /g to 500 m 2 /g and is measured by a BET adsorption method using N 2 .   
     
     
         2 . The secondary battery according to  claim 1 , wherein the organic solvent comprises carbonates. 
     
     
         3 . The secondary battery according to  claim 2 , wherein the carbonates is at least one selected from a group consisting of propylene carbonate, ethylene carbonate, diethyl carbonate, and methylethyl carbonate. 
     
     
         4 . The secondary battery according to  claim 1 , wherein the lithium-containing oxide particles include at least one selected from particles of a lithium ion conductive oxide solid electrolyte having a garnett type structure, and particles of a lithium phosphate solid electrolyte having NASICON type structure. 
     
     
         5 . The secondary battery according to  claim 1 , wherein the negative electrode active material-containing layer contains a titanium-containing oxide. 
     
     
         6 . The secondary battery according to  claim 5 , wherein the titanium-containing oxide comprises at least one selected from a group consisting of a lithium titanium oxide having a spinel structure, a monoclinic titanium oxide, and a niobium titanium oxide. 
     
     
         7 . The secondary battery according to  claim 1 , further comprising a current collector having a first surface and a second surface positioned opposite to the first surface,
 wherein the current collector has a bipolar structure in which the positive electrode active material-containing layer is formed on the first surface of the current collector and the negative electrode active material-containing layer is formed on the second surface.   
     
     
         8 . The secondary battery according to  claim 1 , wherein the positive electrode active material-containing layer contains a positive electrode active material containing at least one selected from a phosphate compound having an olivine structure, and Li x Ni 1−y−z Co y Mn z O 2  where 0<x≤1, 0<y≤1, 0≤z≤1. 
     
     
         9 . The secondary battery according to  claim 8 , wherein the phosphate compound having the olivine structure is represented by Li x Fe 1−y−z Mn y M z PO 4 ,
 wherein:   M is at least one element selected from the group consisting of Mg, Al, Ti, and Zr; and   0≤x≤1.1, 0≤y≤1, and 0≤z≤0.2 are set.   
     
     
         10 . A battery pack comprising the secondary battery according to  claim 1 . 
     
     
         11 . The battery pack according to  claim 10  further comprising:
 an external power distribution terminal; and 
 a protective circuit. 
 
     
     
         12 . The battery pack comprising secondary batteries, each according to  claim 1 ; and
 the secondary batteries are electrically connected in series, in parallel, or in combination of series and parallel.   
     
     
         13 . A vehicle comprising the battery pack according to  claim 10 . 
     
     
         14 . The vehicle according to  claim 13 , wherein the battery pack is configured to recover a regenerative energy of a power of the vehicle. 
     
     
         15 . A composite electrolyte comprising:
 lithium-containing oxide particles having a specific surface area, which is measured by a BET adsorption method using N 2 , of 10 m 2 /g to 500 m 2 /g, and a content of the lithium-containing oxide particles in the composite electrolyte falling within a range of from 90% by weight to 98% by weight; and   an electrolytic composition comprising lithium ions, an organic solvent, and a polymer.