US4937156A
Expired / Lapsed
US
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Process for introducing a hardening sulfuric acid electrolyte into battery cells
Assignee: Deta Akkumulatorenwerk GmbH
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Filing: 1989-01-30
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Granted: 1990-06-26
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Expires: 2009-01-30
Abstract
Abstract A process for introducing a hardening sulfuric acid electrolyte into battery cells at a sulfuric acid density of between 1.20 and 1.31, comprises the steps of combining (A) sulfuric acid, optionally together with up to 3% by weight of suspended silica; (B) a suspension of 6-12% by weight of silica in water; and (C) a water-in-oil emulsion of a polymer polyelectrolyte, in such proportions that the resultant mixture has concentrations of 3-5% by weight of silica and 0.1-1.0% by weight of polymer, and a sulfuric acid density of from 1.20 to 1.31, and intensively mixing the resultant mixture of components A, B and C at a mixing energy of 1-10 kJ/m 3 , whereby inversion of the mixture to an oil-in-water emulsion is initiated; and then immediately filling the mixture into battery cells. The starting components A, B, and C can be stored for a prolonged period. After leaving the mixer, the mixture hardens after about 120-180 seconds.
Inventors
- 👤 Klaus Boeller
- 👤 Gerd Poesch
- 👤 Gerd Hoogestraat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:25
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/06; H01M10/08; H01M10/10; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
189 words
A process for introducing a hardening sulfuric acid electrolyte into battery cells at a sulfuric acid density of between 1.20 and 1.31, which comprises the sequential steps of: (A) combining three initially separate stable components, wherein said components are (i) sulfuric acid at a concentration of 50-80% by weight; (ii) a suspension of 6-12% by weight of silica in water; and (iii) a water-in-oil emulsion of a polyelectrolyte which is a polymer or copolymer of acrylamide having a weight average molecular weight of at least 1,000,000 daltons, wherein said emulsion has a polymer content of 20-60% by weight, a density of ρ=1.03±0.02 g/ml and a viscosity of η=300±100 mPa.s, in such proportions that the resultant mixture has concentrations of 3-5% by weight of silica and 0.1-1.0% by weight of polymer, and a sulfuric acid density of from 1.20 to 1.31; (B) intensively mixing the resultant mixture of components (i), (ii) and (iii) at a mixing energy capable of initiating inversion of the mixture to an oil-in-water emulsion; and (C) immediately filling the mixture into battery cells while the latter are alternately subjected to a higher and a lower pressure.
Claim 2
Dependent Claim
189 words
A process for introducing a hardening sulfuric acid electrolyte into battery cells at a sulfuric acid density of between 1.20 and 1.31, which comprises the sequential steps of: (A) combining three initially separate stable components, wherein said components are (i) sulfuric acid at a concentration of 50-80% by weight; (ii) a suspension of 6-12% by weight of silica in water; and (iii) a water-in-oil emulsion of a polyelectrolyte which is a polymer or copolymer of acrylamide having a weight average molecular weight of at least 1,000,000 daltons, wherein said emulsion has a polymer content of 20-60% by weight, a density of ρ=1.03±0.02 g/ml and a viscosity of η=300±100 mPa.s, in such proportions that the resultant mixture has concentrations of 3-5% by weight of silica and 0.1-1.0% by weight of polymer, and a sulfuric acid density of from 1.20 to 1.31; (B) intensively mixing the resultant mixture of components (i), (ii) and (iii) at a mixing energy capable of initiating inversion of the mixture to an oil-in-water emulsion; and (C) immediately filling the mixture into battery cells while the latter are alternately subjected to a higher and a lower pressure.
Claim 3
Dependent Claim
14 words
The process as claimed in claim 1, wherein the lower pressure is a vacuum.
Claim 4
Dependent Claim
29 words
The process as claimed in claim 2, wherein air is admitted to the battery cells up to atmospheric pressure each time after they have been subjected to a vacuum.
Claim 5
Dependent Claim
15 words
The process as claimed in claim 2, wherein a vacuum of 50-80 kPa is generated.
Claim 6
Dependent Claim
21 words
The process as claimed in claim 2, wherein the repeating frequency for generating the vacuum is between 0.2 and 1 Hz.
Claim 7
Dependent Claim
92 words
An electrolyte filling kit, suitable for use in preparing a hardening sulfuric acid electrolyte in battery cells, comprising in three separate containers: (A) sulfuric acid at a concentration of 50-80% by weight; (B) a suspension of 6-12% by weight of silica in water; and (C) a water-in-oil emulsion of a polyelectrolyte which is a polymer or copolymer of acrylamide having a weight average molecular weight of at least 1,000,000 daltons, wherein said emulsion has a polymer content of 20-60% by weight, a density of ρ=1.03±0.02 g/ml and a viscosity of η=300±100 mPa.s.
Claim 8
Dependent Claim
92 words
An electrolyte filling kit, suitable for use in preparing a hardening sulfuric acid electrolyte in battery cells, comprising in three separate containers: (A) sulfuric acid at a concentration of 50-80% by weight; (B) a suspension of 6-12% by weight of silica in water; and (C) a water-in-oil emulsion of a polyelectrolyte which is a polymer or copolymer of acrylamide having a weight average molecular weight of at least 1,000,000 daltons, wherein said emulsion has a polymer content of 20-60% by weight, a density of ρ=1.03±0.02 g/ml and a viscosity of η=300±100 mPa.s.
Claim 9
Dependent Claim
26 words
The kit as claimed in claim 6, wherein in component A, said sulfuric acid is admixed with not more than 3% be weight of suspended silica.
Claim 10
Dependent Claim
25 words
The kit as claimed in claim 7, wherein said silica content is in the range of 1.3-1.5% by weight of the first starting component A.
Claim 11
Dependent Claim
22 words
The kit as claimed in claim 6, wherein the silica content is about 8% by weight in the second starting component B.
Claim 12
Dependent Claim
22 words
The kit as claimed in claim 6, wherein the polymer content in the emulsion is about 40% by weight in component C.
Claim 13
Dependent Claim
16 words
The kit as claimed in claim 6, wherein the silica used is pyrogenic SiO 2 .
Claim 14
Dependent Claim
15 words
The kit as claimed in claim 11, wherein silica of the hydrophilic type is used.
Claim 15
Dependent Claim
24 words
The kit as claimed in claim 12, wherein silica of the hydrophobic type with surfactants as an additive is added to the hydrophilic silica.
References Cited (Backward Citations)
GB166707A
Cited
GB571305A
Cited
US3402077A
Cited
US3305396A
Cited
US3776779A
Cited
US4391036A
Cited
DE3539834A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |