Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/06—Lead-acid accumulators
  • H01M10/12—Construction or manufacture
  • H01M10/128—Processes for forming or storing electrodes in the battery container
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/34—Gastight accumulators
  • H01M10/342—Gastight lead accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0002—Aqueous electrolytes
  • H01M2300/0005—Acid electrolytes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• The. present invention relates to lead acid electric storage batteries, and is particularly concerned with
• Recombinant lead acid batteries are known.
• the cells of .such batteries usually have a highly absorbent separator material separating the electrodes and the amount of electrolyte added is such that the cells at least when fully charged contain substantially no free
• OMPI the active material rather than vice versa and patches of alkalinity may occur which are conducive to the formation of soluble lead compounds which become precipitated in the separator during electrolytic 5. formation.
• the invention can be used with individual cells ' e.g. spirally wound cells or 'with batteries of cells.
• the invention has been developed with a par icu- 15. lar battery configuration in mind and is described with reference thereto but is not to be construed as being limited in its usefulness to such a battery.
• a method of 20. making a lead acid electric storage battery or cell comprises enclosing the cell group or groups in cell containers, evacuating the cells and introducing sulphuric acid electrolyte into the cells in an amount such that the cells are not flooded and within 2 * 5. less than 6 hours preferably less than 4 hours and especially less than 2 hours of the first contact of the acid with the active material, commencing electro ⁇ lytic formation of the cells in the cell containers.
• the cells are preferably allowed to cool to a
• OMP temperature not in excess of 40 C before electrolytic formation is commenced Preferably the electrolytic formation is commenced within less than hour of the first contact of the acid with the active material
• the method is applied to the production of a lead acid electric storage battery, and especially a battery adapted to provide one or more of the starting, lighting or
• ignition battery functions for a vehicle in which the positive and negative plates in each cell are separated by separators of electrolyte and gas permeable compressible fibrous .separator material having an electrolyte absorption ratio of at least
• the volume E of electrolyte in the battery pre ⁇ ferably being at least 0.8 (X+Y), where X is the total pore volume of the separators in the dry state and Y is the total pore volume of the positive and negative active materials in the dry fully charged state, the
• the volume of electrolyte is. desirably in the range 0.8 (X+Y) to 0.99 (X+Y) and especially at least 0.9 (X+Y) or even at least 0.95 (X+Y).
• OMPI_ values enable the active material to be utilized more efficiently than when lower amounts of electrolyte are used.
• the ratio of X to Y may be in the range 6:1 to
• the electrolyte active material ratio is at least 0.05 e.g. at least 0.06 or at least 0.10 and is the ratio of HdonS0 u in grams to the lead in the active
• ial on a weight of lead basis
• ratios below 1:1 is contrary to what is conventional for recombinant batteries but we find that recombinant operation can be achieved at these ratios and they
• ratios in the range 0.6:1 to 0.99:1 e.g. 0.7:1 to 0.9:1.
• the separator material is a
• compressible absorbent fibrous material e.g. having
• O PI an electrolyte absorption ratio of at least 100% e.g. 100 to 200% especially 110 to 170%. It is electrically non-conducting and electrolyte-resistant.
• Electrolyte absorption ratio is the ratio, as a
• aqueous sulphuric acid electrolyte of 1.270 SG con ⁇ taining 0.01% by weight sodium lauryl sulphonate with 1 cm of the lower end of the strip immersed in the electrolyte after a steady state wicking condition has been reached at 20 C at a relative h ⁇ midity of less
• the thickness of the separator material is measured with a micrometer at a loading of 10 kilo- pascals C1.45 psi) and a foot area of 200 square millimetres (in accordance with the method of British
• fibrous hotting paper-like materials made from fibres having diameters in the range 0.01 microns or less up
• the average of the diameters of the fibres being less than 10 microns, and preferably less than 5 microns, the weight to fibre density ratio, namely the ratio of the weight of the fibrous material in grams/square metre to the density in grams/cubic
• centimetre of the material from which the individual fibres are made preferably being at least 20 prefer ⁇ ably at least 30 and especially at least 50.
• Recombinant lead acid batteries in which gas recombination is used to eliminate maintenance during use, operate under superatmospheric . pressure e.g. from 1 bar (atmospheric pressure) upwards and due to
• the battery operates under the so-called "oxygen cycle".
• negative active material enables the negative elec ⁇ trode to effect recombination of the oxygen produced by the positive electrode even at the beginning of the charge cycle. Thus it may -not be necessary to have an excess weight of negative active material
• the capacity of the negative electrodes in each cell will normally and desirably always be in excess of that of the posi ⁇ tive electrodes.
• the electrochemical efficiency of the negative electrodes is in general greater than that of the positive electrodes but it must be born in mind that the efficiency of the negative electrodes drops more rapidly than that of the positive electrodes both as the cells undergo increasing numbers of cycles of charge and discharge and as the temperature of operation is reduced below ambient (i.e. 25 C) . Excess negative capacity may thus conveniently be
• a separator desirably having a high electrolyte absorp ⁇ tion ratio as also described and defined above, which is compressible, so as to conform closely to the sur- • faces of the electrodes , and -which has wicking or capillary activity, whereby transmission of electrolyte
• the charging conditions generate oxygen at a faster rate than ' it can be transported to the negative and react thereat, then the excess oxygen is vented from the battery.
• the container of the battery is thus provided at least with gas venting means.
• the gas venting means preferably take the form of a non-return valve so that air cannot obtain access 5. to the interior of the battery although gas generated therein can escape to atmosphere.
• the lid of the container may be formed with filling apertures to permit electrolyte to be intro ⁇ quizd into each cell.
• The- filling apertures may be 10. closed after the electrolyte has been added but the closures should provide gas venting means • or separate gas venting means should be provided.
• Figure 1 is a partial cross-sectional side elevation of part of a starting, lighting and ignition 20. battery in accordance with the present invention
• Figure 2 is an end elevation on the line II-II of Figure 1;
• Figure 3 is an electron scanning photomicrograph of a preferred separator material at 1000 fold agnifi- 25. cation.
• Figure 4 is a view similar to Figure 3 at 4000 fold magnification.
• the battery has a capacity of 43 Ahr and has six cells accommodated in a container 2 made as a single 30. moulding of polypropylene plastics material and
• Each cell contains four positive plates 10 inter-
• separators 14 of electrolyte and gas perm ⁇ eable compressible blotting paper-like glass fibre material whose composition and function will be des ⁇ cribed below. A sheet of separator 14 is also placed
• the positive plates 10 and negative plates 12 are formed from a cast grid of lead alloy containing 0.07% calcium and 0.7% tin and carry positive and negative active elec ⁇ trode material respectively.
• the positive plates are 2.0 mms thick and the negative plates are 1.8 mms thick and are held in inti ⁇ mate contact with the separators by solid polypropylene packing pieces 30. Both faces of all plates are covered by separator material which extends out above
• the plates may be 1 to 2 mms thick e.g. 1.2 to 1.9 or 1.2 to 1.6 mms thick.
• the positive is 1.4 mms thick and the negative is 1.2 mms thick.
• the positive active material had the following composition before being electrolytically formed: Hardinge grey oxide 13640 parts, fibre 6 parts, water 1800 parts, 1.40 SG aqueous sulphuric acid 750 parts.
• the negative active material had the following composition before being electrolytically formed: Hardinge oxide 13640 parts, fibre 3 parts, barium sulphate 68 parts, carbon black 23 parts, stearic
• Vanisperse CB (a lignosulphonate) 41 parts, water 1525 parts, 1.40 SG aqueous sulphuric acid 875 parts.
• the paste had a density of 4.3. Vanisperse CB is described in British patent specifi ⁇ cation No. 1,396,308.
• Each positive plate carried 109 grams of positive active material on a dry weight basis.
• Each negative plate carried 105 grams of nega ⁇ tive active material on a dry weight basis.
• the separators 14 are highly absorbent blotting
• the separator 14 weighs 200 grams/square metre and has a porosity of 90-95% as measured by mercury intrusion penetrometry.
• Each sheet of separator material is 1 mms thick and weighs 200 grams/square metre.
• the total volume of separator for each cell before assembly is 218
• the separator in the cell is compressed by about 8% and thus the volume of separator in the cell is 200.6 cubic centimetres.
• the separators being compressible conform closely
• the total .thickness of separator should desirably be no thinner than about 0.6 mms since below this
• the total geometric surface area of. the positive plates in each cell is 767 square centimetres and of the negative plates 959 square centimetres.
• the dry weight of the active material of the positive plates is 767 square centimetres and of the negative plates 959 square centimetres.
• the true density of the positive active material (Pb0_) in the fully charged state is 9 gr/cc and the true density of the negative active material (sponge lead) in the fully charged state is 10.5 gr/cc.
• the true volume of the positive active material is 4 x 109 ⁇ 9 i.e. 48.4 ccs and the true volume of the negative active material is 5 x 105 ⁇ 10.5 i.e. 50 ccs.
• the apparent density of the dry positive active material is 4.2 gr/cc and thus the apparent volume of the dry positive active material is 4 x 109 ⁇ 4.2 i.e. 103.8 ccs.
• the apparent density of the. dry negative active material is 4.4 gr/cc and thus the
• apparent volume of the dry negative active material is 5 x 105 ⁇ 4.4 i.e. 119.3 ccs.
• the pore volume of the positive active material is 55.4 ccs and of the negative active material is 69.3 ccs and the total pore volume of
• the active material is 124.7 ccs, which is the value of Y.
• the ratio of X to Y is thus 1.45:1 to 1.53:1. (X+Y) is 305.2 to 315.3.
• the calculated true surface area for the positive active material is 1170 square metres and for the
• the electrolytic forming regime comprised 24 hours at 4.4 amps followed by 24 hours at 0.9 amps.
• the amount of electrolyte remaining is thus 0.99 (X+Y) to 0.96 (X+Y).
• the battery contained 0.7 ml of 1.275 SG aqueous sulphuric acid per gram of positive active material (as lead) and 0.66 ml of 1.275 SG aqueous sulphuric acid per gram of negative active material as lead.
• the battery contained 0.34 ml of 1.275 SG aqueous sulphuric
• the positive and negative plates are inter- 30. connected by a respective positive and negative group
• intercell partition 4 and overlies a hole 22 in the partition.
• the positive flag in the left hand of the two cells shown in Figure 1 is connected to the similar negative flag in the right hand cell through- the hole 22 so as to form an intercell connection by a method
• the positive group bar in the right hand cell is provided with a flag 24.
• the flag 24 is connected to a terminal 26 in the lid of the container.
• Each cell of the battery is normally sealed, that is to say that during normal operation of the battery the cells do not communicate with the atmos ⁇ phere. However in case a substantial over-pressure should build up in the cell, for instance because
• the cell is exposed to a very high temperature or over-charged, so that oxygen gas is evolved at a faster rate than it can be combined, a non-return relief valve is provided to exhaust the excess gas and is arranged to operate at a pressure of only 2
• Each valve is of the Bunsen type and comprises a passage 36 communicaxing with the interior of a cell and leading to the exterior of the lid.
• Each passage 36 is within a boss in a respective recess 38 in the lid, and the boss is s ⁇ alingly covered by a
• resilient cap 40 having a depending skirt around the boss.
• the cap 40 normally seals the passage 36, but if an excessive pressure should occur in the battery the skirt of the cap lifts away from the boss to vent the cell.
• a disc 42 provided with a vent hole or
• electrodes could be made from, slit expanded sheet or be of wrought form e.g. perforated or punched sheet or from fibrous supports provided with electrically conductive coat ⁇ ings or deposited conductors such as are disclosed in 0. the present applicants British applications Nos.
• the grids are preferably 0.1 to 3.0 mms thick especially 1.5 to 2.5 mms thick.
• the preferred alloy is a lead calcium tin alloy prefer ⁇ ably containing 0.06 to 0.13% e.g. 0.07 to 0.09%
• Alternative alloys include 99.9% lead and anti- monial alloys such as those disclosed in United States patents Nos. 3879217 and 3912537.
• the battery will not need topping up with electrolyte and is therefore maintenance free. Furthermore the battery is unspill- able firstly because it is sealed and secondly because there is substantially no free electrolyte in the
• the invention is applicable to recombinant lead acid electric storage batteries and cells.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Secondary Cells (AREA)
• Organic Insulating Materials (AREA)
• Inorganic Insulating Materials (AREA)

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• 1980
  • 1980-05-08 IN IN544/CAL/80A patent/IN152679B/en unknown
  • 1980-05-08 AU AU59922/80A patent/AU5992280A/en not_active Abandoned
  • 1980-05-08 WO PCT/GB1980/000084 patent/WO1980002474A1/en not_active Application Discontinuation
  • 1980-05-09 ES ES491333A patent/ES491333A0/es active Granted
  • 1980-05-09 ZA ZA00802797A patent/ZA802797B/xx unknown
  • 1980-11-17 EP EP80900780A patent/EP0028228A1/en not_active Withdrawn

Non-Patent Citations (1)

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