Electroactive materials for metal-ion batteries

Patent metadata

Field	Value
Publication number	US-2018069234-A1
Application number	US-201615558446-A
Country	US
Kind code	A1
Filing date	Mar 16, 2016
Priority date	Mar 16, 2015
Publication date	Mar 8, 2018
Grant date	—

Abstract

A process is provided for preparing a particulate material consisting of a plurality of porous particles comprising an electroactive material selected from silicon, tin, germanium, aluminium or a mixture thereof, wherein the particles are assembled from a plurality of particle fragments comprising the electroactive material wherein the fragments are obtained by the fragmentation of a porous precursor. The fragmentation step may be realized e.g. by wet ball milling and the later assembling step is preferably realized by spray-drying. Also provided are particulate materials obtainable according to the process of the invention, compositions comprising the particulate materials, and electrodes and electrochemical cells comprising the particulate materials. The materials and compositions are especially useful as anode materials in the context of a metal-ion battery such as a lithium-ion battery.

First claim

1 . A process for preparing a particulate material consisting of a plurality of porous particles comprising at least 30% by weight of an electroactive material selected from silicon, tin, germanium, aluminium or a mixture thereof, the process comprising assembling the porous particles from a plurality of fragments comprising the electroactive material, wherein the fragments are obtainable via the fragmentation of a porous precursor comprising the electroactive material.

2 . A process according to claim 1 , wherein the fragments comprise at least 40 wt %, preferably at least 50 wt %, more preferably at least 60 wt %, more preferably at least 70 wt %, more preferably at least 75 wt %, more preferably at least 80 wt %, and most preferably at least 85 wt % of the electroactive material.

3 . A process according to claim 1 or claim 2 , wherein the fragments comprise at least 40 wt %, preferably at least 50 wt %, more preferably at least 60 wt %, more preferably at least 70 wt %, more preferably at least 75 wt %, more preferably at least 80 wt %, and most preferably at least 85 wt % of silicon.

4 . A process according to claim 3 , wherein the fragments comprise at least 60 wt % silicon and up to 40 wt % aluminium and/or germanium, preferably at least 70 wt % silicon and up to 30 wt % aluminium and/or germanium, more preferably at least 75 wt % silicon and up to 25 wt % aluminium and/or germanium, more preferably at least 80 wt % silicon and up to 20 wt % aluminium and/or germanium, more preferably at least 85 wt % silicon and up to 15 wt % aluminium and/or germanium, more preferably at least 90 wt % silicon and up to 10 wt % aluminium and/or germanium, and most preferably at least 95 wt % silicon and up to 5 wt % aluminium and/or germanium.

5 . A process according to any one of the preceding claims, wherein the fragments comprise a minor amount of one or more additional elements selected from antimony, copper, magnesium, zinc, manganese, chromium, cobalt, molybdenum, nickel, beryllium, zirconium, iron, sodium, strontium, phosphorus, ruthenium, gold, silver, and oxides thereof.

6 . A process according to any one of the preceding claims, wherein the fragments have a D 50 particle diameter of at least 300 nm, preferably at least 500 nm, optionally at least 800 nm or at least 1 μm.

7 . A process according to any one of the preceding claims, wherein the fragments have a D 50 particle diameter of no more than 10 μm, preferably no more than 8 μm, more preferably no more than 6 μm, more preferably no more than 4 μm, more preferably no more than 2 μm, and most preferably no more than 1.5 μm.

8 . A process according to any one of the preceding claims, wherein the fragments have a D 10 particle diameter of at least 100 nm, preferably at least 200 nm, more preferably at least 300 nm, and optionally at least 400 nm, at least 500 nm or at least 600 nm.

9 . A process according to any one of the preceding claims, wherein the fragments have a D 90 particle diameter no more than 15 μm, preferably no more than 10 μm, more preferably no more than 8 μm, more preferably no more than 6 μm, and most preferably no more than 4 μm.

10 . A process according to any one of the preceding claims, wherein the fragments have a fragment size distribution span of 5 or less, preferably 4 or less, preferably 3 or less, more preferably 2 or less and most preferably 1.5 or less.

11 . A process according to any one of the preceding claims, wherein the fragments comprise a plurality of elongate structural elements having an average minimum dimension in the range of from 10 nm to 500 nm.

12 . A process according to any one of the preceding claims, wherein the fragments comprise a plurality of elongate structural elements having an aspect ratio of at least 2:1, preferably at least 3:1, more preferably at least 4:1 and most preferably at least 5:1.

13 . A process according to any one of the preceding claims, wherein the fragments are obtained from the fragmentation of a porous precursor comprising elongate structural elements having an average minimum dimension in the range of from 10 nm to 500 nm.

14 . A process according to any one of the preceding claims, wherein the fragments are obtained from the fragmentation of a porous precursor comprising elongate structural elements having an aspect ratio of at least 2:1, preferably at least 3:1, more preferably at least 4:1 and most preferably at least 5:1.

15 . A process according to any one of the preceding claims, wherein the fragments are obtained from the fragmentation of a porous precursor in the form of porous particles having a D 50 particle diameter in the range of from 5 μm to 5 mm.

16 . A process according to any one of the preceding claims, wherein the fragments are obtained from the fragmentation of a porous precursor having internal porosity of at least 40%, preferably at least 50%, and most preferably at least 60%.

17 . A process according to any one of the preceding claims, wherein the fragments are obtained from the fragmentation of a porous precursor having a pore diameter distribution having a peak corresponding to the internal or intra-particles pores in the range of from 50 nm to less than 500 nm as determined by mercury porosimetry.

18 . A process according to any one of the preceding claims, wherein the fragments are obtained from wet ball milling of a porous precursor.

19 . A process according to any one of the preceding claims, wherein the porous precursor is obtainable by leaching an alloy comprising silicon and/or germanium structures dispersed in a metal matrix.

20 . A process according to any one of the preceding claims, wherein the porous particles are assembled from the plurality of fragments and one or more further components selected from conductive additives, structural additives, pore forming materials and additional particulate electroactive materials.

21 . A process according to any one of the preceding claims, wherein the porous particles are assembled in the presence of a binder, preferably wherein the binder is a polymeric binder or a carbonisable binder.

22 . A process according to any one of the preceding claims, wherein the porous particles are assembled by spray drying, agglomeration, granulation, lyophilisation, freeze granulation, spray-freezing into liquid, spray pyrolysis, electrostatic spraying, emulsion polymerisation and self-assembly of particles in solution.

23 . A process according to claim 22 , comprising forming a slurry comprising the fragments and optionally any conductive additives and/or structural additives and/or additional particulate electroactive materials and/or binders together with a vaporisable liquid carrier, and spray drying the slurry to form the particulate material consisting of a plurality of porous particles.

24 . A process according to any one of the preceding claims, wherein the porous particles comprise at least 50 wt %, preferably at least 60 wt %, more preferably at least 70 wt % and most preferably at least 75 wt % of the fragments.

25 . A process according to any one of the preceding claims, wherein the porous particles comprise at least 40 wt %, at least 50 wt %, preferably at least 60 wt %, more preferably at least 70 wt %, more preferably at least 75 wt %, more preferably at least 80 wt %, and most preferably at least 85 wt % of the electroactive material.

26 . A process according to any one of claims 1 to 20 , compri

Assignees

• Nexeon Ltd

Inventors

• Friend Christopher Michael
• Mason Charles
• Wernicke Fritz Wilhelm
• Murphy Lisa

Classifications

• C01B33/02

  Silicon (forming single crystals or homogeneous polycrystalline material with defined structure C30B) · CPC title

• H01M4/622

  being polymers · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title