Cathodic electrode of a lithium-based accumulator

Patent metadata

Field	Value
Publication number	US-9755224-B2
Application number	US-201514943163-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Nov 19, 2014
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A cathodic electrode of a lithium-based accumulator includes a basic structure, which is formed from fibers, flakes or grains. For this purpose, the fibers, flakes or grains are interspersed with channels, cavities or open pores.

First claim

What is claimed is:

1. A lithium-based accumulator, comprising:
an anode electrode;
a cathode electrode;
a separator region between the anode electrode and the cathode electrode;
wherein:
the cathode electrode includes a current collector and an electrochemically active layer;
the electrochemically active layer includes a plurality of basic structures that are formed as at least one of fibers, flakes, and grains and that include a conductive material core surrounded by a non-electrochemically active polymer in which are interspersed at least one of channels, cavities, and open pores that open to a surface of the basic structures.

2. The lithium-based accumulator of claim 1 , wherein, the basic structures include grains interspersed with tubular cavities with a cavity depth of up to half of an average grain diameter.

3. The lithium-based accumulator of claim 2 , wherein the average grain diameter is in the range of 50 to 500 nm, and the cavity depth is in the range of 10 to 300 nm.

4. The lithium-based accumulator of claim 1 , wherein the basic structures include fibers interspersed with cavities that are configured in a lamellar manner on a surface of the respective fibers and that have a length that extends in a direction approximately parallel to longitudinal axes of the respective fibers.

5. The lithium-based accumulator of claim 4 , wherein the cavities have in the direction of the fiber longitudinal axes a cavity length of approximately half of an average fiber diameter.

6. The lithium-based accumulator of claim 5 , wherein the average fiber diameter is in the range of 150 nm to 1 μm.

7. The lithium-based accumulator of claim 1 , wherein the basic structures include flakes that have a length, a width, and a depth that is less than the width, and the flakes are interspersed with cavities, the cavities being configured on the surface of the flakes in a circular or lamellar manner and having a depth of at most two thirds of an average thickness of the respective flakes.

8. The lithium-based accumulator of claim 1 , wherein the at least one of channels, cavities, and open pores have a circular cross section on the surface of the at least one of fibers, flakes, and grains, and an average distance between pairs of adjacent ones of the at least one of channels, cavities, and open pores is between a one-fold and a five-fold of an average diameter of the circular cross section.

9. The lithium-based accumulator of claim 1 , wherein a layer thickness of the non-electrochemically active polymer is a quarter up to a two-fold, three-fold or five-fold of the thickness of the core.

10. The lithium-based accumulator of claim 1 , wherein the basic structures include fibers or grains interspersed with channels or open pores, an average fiber or grain diameter is from 0.1 to 5 μm and an average channel diameter or pore diameter is from 0.05 to 0.4 μm.

11. The lithium-based accumulator of claim 1 , wherein the basic structures include fibers or grains interspersed with channels or open pores, an average fiber or grain diameter is from 0.3 to 2 μm, and an average channel diameter or pore diameter is from 0.1 to 0.3 μm.

12. The lithium-based accumulator of claim 1 , wherein the basic structures include fibers or grains interspersed with channels or open pores, an average fiber or grain diameter is from 0.5 to 2 μm, and an average channel diameter or pore diameter is from 0.1 to 0.3 μm.

13. The lithium-based accumulator of claim 1 , wherein all of the at least one of channels, cavities, and open pores are completely separated from the core by the polymer.

14. The lithium-based accumulator of claim 1 , wherein the at least one of channels, cavities, and open pores open to a boundary of the separator region, the separator region including an electrolyte.

15. The lithium-based accumulator of claim 1 , wherein the at least one of channels, cavities, and open pores are filled with electrochemically active material.

16. The lithium-based accumulator of claim 1 , wherein the at least one of channels, cavities, and open pores are filled with sulfur sulfides or polysulfides.

17. The lithium-based accumulator of claim 1 , wherein the conductive material core is made of a conductive oxide.

Assignees

• Bosch Gmbh Robert

Inventors

• Schumann Bernd
• Fanous Jean

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/624

  Electric conductive fillers · CPC title

• H01M4/13 Primary

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M2004/028

  Positive electrodes · CPC title