Tin silicon anode active material

Patent metadata

Field	Value
Publication number	US-2017294643-A1
Application number	US-201715480904-A
Country	US
Kind code	A1
Filing date	Apr 6, 2017
Priority date	Apr 7, 2016
Publication date	Oct 12, 2017
Grant date	—

Abstract

Improved anodes and cells are provided, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion. Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth. Various anode active materials and combinations, modifications through nanoparticles and a range of coatings which implement the improved anodes are provided.

First claim

1 . An anode comprising anode active material particles which comprise tin.

2 . The anode of claim 1 , wherein the anode active material particles comprise 5-80% tin.

3 . The anode of claim 2 , wherein the anode active material particles further comprise at least one of germanium, silicon, boron, alloys and mixtures thereof.

4 . The anode of claim 2 , wherein the anode active material particles further comprise nanoparticles attached thereto, wherein the nanoparticles are at least one order of magnitude smaller than the anode active material particles.

5 . The anode of claim 4 , wherein the anode active material particles are 100-500 nm in diameter and have nanoparticles attached thereto which are 10-50 nm in diameter.

6 . The anode of claim 4 , wherein the nanoparticles are embedded in the anode active material particles.

7 . The anode of claim 4 , wherein the nanoparticles are made of boron carbide and/or tungsten carbide.

8 . The anode of claim 7 , wherein the nanoparticles are B 4 C nanoparticles, which are attached at between 2-25 weight % of the anode active material particles.

9 . The anode of claim 4 , wherein the anode active material particles further comprise a 1-10 nm thick surface layer of any of: an amorphous carbon, graphene and graphite.

10 . The anode of claim 4 , wherein the anode active material particles further comprise a 1-10 nm thick surface layer of a transition metal.

11 . The anode of claim 4 , wherein the anode active material particles further comprise a 1-10 nm thick surface layer of a lithium polymer.

12 . The anode of claim 11 , wherein the surface layer comprises a buffering zone configured to receive lithium ions from an interface of the anode active material particles with an electrolyte, partially reduce the received lithium ions, and enable the partially reduced lithium ions to move into an inner zone of the anode active material particles for lithiation therein.

13 . The anode of claim 1 , wherein the anode active material particles further comprise a coating by a polymer which is conductive and/or lithiated.

14 . The anode of claim 13 , wherein the anode active material particles are 20-500 nm in diameter and the coating is 2-200 nm thick.

15 . A lithium ion cell comprising the anode of claim 1 .

16 . A method of making a Li-ion energy storage device, comprising: combining metalloid particles having a particle size of 100-500 nm and comprising a metalloid selected from the group consisting of Sn, Pb, Ge, Si, and alloys thereof, with B 4 C nanoparticles having a particle size of 10-50 nm, to form an anode active material.

17 . The method of claim 16 , wherein said combining is performed by milling the metalloid particles and B 4 C nanoparticles together to embed the B 4 C nanoparticles in a surface of the metalloid particles.

18 . A method comprising preparing an anode for a lithium ion cell from tin active material particles by forming a slurry with the tin active material particles, a solvent, and at least one additive selected from the group consisting of conductive particles, binder and plasticizer; and removing solvent and consolidating the slurry to form an anode.

19 . The method of claim 18 , wherein the tin active material particles comprise 5-80% tin, further comprise at least one of Si, Ge, B and W, and have a particle size of 100-500 nm.

20 . The method of claim 19 , further comprising attaching B 4 C and/or WC nanoparticles to the tin active material particles, wherein the B 4 C and/or WC nanoparticles have a particle size of 10-50 nm.

Assignees

• Storedot Ltd

Inventors

• Burshtain Doron
• Remizov Sergey
• Jacob David
• Shadmi Nitzan
• FARRAN Hani
• Shapiro Leora
• Goldbart Ohad
• Brudnik Boris
• Ophir Carmit
• Aronov Daniel

Classifications

• H01M4/624

  Electric conductive fillers · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title