Electrode, secondary battery, battery pack, and vehicle
According to one embodiment, an electrode is provided. The electrode includes an active material-containing layer. The active material-containing layer contains an active material and a flat plate-shaped silicate.
1. An electrode, comprising:
an active material-containing layer comprising an active material and a flat plate-shaped silicate,
wherein the active material-containing layer does not comprise a carboxymethyl cellulose,
wherein a thickness of the flat plate-shaped silicate is within a range from 0.2 nm to 100 nm,
wherein a length in a shorter direction of the flat plate-shaped silicate is within a range from 3 nm to 900 nm, and
wherein an aspect ratio of the length in the shorter direction of the flat plate-shaped silicate to the thickness of the flat plate-shaped silicate is within a range from 5 to 25.
2. The electrode according to claim 1 , wherein
the thickness of the flat plate-shaped silicate is within a range from 0.5 nm to 50 nm.
3. The electrode according to claim 1 , wherein
the length in a shorter direction of the flat plate-shaped silicate is within a range from 10 nm to 300 nm.
4. The electrode according to claim 1 , wherein
a ratio of a mass of the flat plate-shaped silicate to a mass of the active material is within a range from 0.01 to 0.1 in the active material-containing layer.
5. The electrode according to claim 1 , wherein
the active material comprises a monoclinic niobium titanium composite oxide.
6. The electrode according to claim 1 , wherein
the flat plate-shaped silicate is at least one kind selected from the group consisting of hectorite, saponite, and montmorillonite.
7. The electrode according to claim 1 , wherein
the active material-containing layer further comprises a dispersing agent, and
the dispersing agent is a water-soluble material having anionicity or cationicity.
8. A secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte, wherein
the negative electrode is the electrode according to claim 1 .
9. A battery pack comprising
the secondary battery according to claim 8 .
10. The battery pack according to claim 9 , further comprising:
an external power distribution terminal; and
a protective circuit.
11. The battery pack according to claim 9 , comprising
a plurality of the secondary batteries, wherein
the plurality of the secondary batteries are electrically connected in series, in parallel, or in a combination of series connection and parallel connection.
12. A vehicle comprising the battery pack according to claim 9 .
13. The vehicle according to claim 12 , further comprising a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.
14. The electrode according to claim 1 , wherein
the active material-containing layer comprises the active material, a conductive agent, a binder, and a thickening agent at ratios in a range from 70% by mass to 96% by mass or less, in a range from 2% by mass to 28% by mass, in a range from 2% by mass to 28% by mass, and in a range from 2% by mass to 28% by mass, respectively, and
the thickening agent consists of the flat plate-shaped silicate.
15. The electrode according to claim 1 , wherein the flat plate-shaped silicate is a thickening agent.
16. The electrode according to claim 1 , wherein a thickening agent is present in the active material-containing layer in a range of from 1 to 5 parts by mass.