Secondary battery, battery pack, electric vehicle, electric power storage system, electric power tool, and electronic apparatus
A secondary battery includes: a cathode including a cathode current collector and a first cathode active material layer provided on the cathode current collector; an anode including an anode current collector and a first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound; an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and a second cathode active material layer provided on the intermediate current collector to face the first anode active material layer; and an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent.
1. A secondary battery, comprising:
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector;
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound;
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer;
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent;
a first separator provided between the cathode and the intermediate electrode; and
a second separator provided between the anode and the intermediate electrode.
2. The secondary battery according to claim 1 , wherein a content of the electrolyte salt with respect to the solvent is 2 mol/kg or more.
3. The secondary battery according to claim 2 , wherein the content of the electrolyte salt with respect to the solvent is 3 mol/kg or more.
4. The secondary battery according to claim 1 , wherein
the solvent includes propylene carbonate and the electrolyte salt includes lithium tetrafluoroborate (LiBF 4 ),
the solvent includes propylene carbonate and the electrolyte salt includes lithium hexafluorophosphate (LiPF 6 ), or
the solvent includes acetonitrile and the electrolyte salt includes lithium bis(fluorosulfonyl)amide (LiN(SO 2 F) 2 ).
5. The secondary battery according to claim 1 , wherein the titanium-containing compound includes one or more of a titanium oxide represented by the following formula (1) and respective lithium-titanium composite oxides represented by the following formulas (2), (3), and (4),
TiO w (1)
where w satisfies 1.85<w≤2.15,
Li[Li x M1 (1−3x)/2 Ti (3+x)/2 ]O 4 (2)
where M1 is one or more of magnesium (Mg), calcium (Ca), copper (Cu), zinc (Zn), and strontium (Sr), and “x” satisfies 0≤x≤1/3,
Li[Li y M2 1−3y Ti 1+2y ]O 4 (3)
where M2 is one or more of aluminum (Al), scandium (Sc), chromium (Cr), manganese (Mn), iron (Fe), germanium (Ge), gallium (Ga), and yttrium (Y), and “y” satisfies 0≤x≤1/3, and
Li[Li 1/3 M3 z Ti (5/3−z ]O 4 (4)
where M3 is one or more of vanadium (V), zirconium (Zr), and niobium (Nb), and “z” satisfies 0≤z≤2/3.
6. The secondary battery according to claim 1 , wherein the secondary battery is a lithium-ion secondary battery.
7. A battery pack, comprising:
a secondary battery;
a controller that controls an operation of the secondary battery; and
a switch section that switches the operation of the secondary battery in accordance with an instruction from the controller,
the secondary battery including
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector,
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound,
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer,
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent,
a first separator provided between the cathode and the intermediate electrode, and
a second separator provided between the anode and the intermediate electrode.
8. An electric vehicle, comprising:
a secondary battery;
a converter that converts electric power supplied from the secondary battery into drive power;
a drive section that operates in accordance with the drive power; and
a controller that controls an operation of the secondary battery,
the secondary battery including
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector,
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound,
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer,
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent,
a first separator provided between the cathode and the intermediate electrode, and
a second separator provided between the anode and the intermediate electrode.
9. An electric power storage system, comprising:
a secondary battery;
one or more electric devices that are supplied with electric power from the secondary battery; and
a controller that controls the supplying of the electric power from the secondary battery to the one or more electric devices,
the secondary battery including
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector,
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound,
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer,
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent,
a first separator provided between the cathode and the intermediate electrode, and
a second separator provided between the anode and the intermediate electrode.
10. An electric power tool, comprising:
a secondary battery; and
a movable section that is supplied with electric power from the secondary battery,
the secondary battery including
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector,
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound,
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer,
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent,
a first separator provided between the cathode and the intermediate electrode, and
a second separator provided between the anode and the intermediate electrode.
11. An electronic apparatus comprising a secondary battery as an electric power supply source, the secondary battery including
a cathode including a cathode current collector and a first cathode active material layer, the first cathode active layer provided on the cathode current collector,
an anode including an anode current collector and a first anode active material layer, the first anode active material layer provided on the anode current collector to face the first cathode active material layer and including a titanium-containing compound,
an intermediate electrode provided between the cathode and the anode and including an intermediate current collector, a second anode active material layer, and a second cathode active material layer, the second anode active material layer provided on the intermediate current collector to face the first cathode active material layer and including the titanium-containing compound, and the second cathode active material layer provided on the intermediate current collector to face the first anode active material layer,
an electrolytic solution including a solvent and an electrolyte salt and having number of molecules of the electrolyte salt equal to or larger than number of molecules of the solvent,
a first separator provided between the cathode and the intermediate electrode, and
a second separator provided between the anode and the intermediate electrode.