(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2003/0118912 A1
`Watanabe et al.
`(43) Pub. Date:
`Jun. 26, 2003
`
`US 2003.01.18912A1
`
`(54) ELECTROLYTIC SOLUTION FOR
`NON-AQUEOUS TYPE BATTERY AND
`NON-AQUEOUS TYPE SECONDARY
`BATTERY
`(76) Inventors: Shoichiro Watanabe, Ikoma-gun (JP);
`Shusaku Goto, Moriguchi-shi (JP);
`Masaru Takagi, Moriguchi-shi (JP);
`Sumihito Ishida, Moriguchi-shi (JP);
`Toshikazu Hamamoto, Ube-shi (JP);
`Akira Ueki, Ube-shi (JP)
`Correspondence Address:
`STEVENS DAVIS MILLER & MOSHER, LLP
`1615 LSTREET, NW
`SUTE 850
`WASHINGTON, DC 20036 (US)
`(21) Appl. No.:
`10/333,617
`(22) PCT Filed:
`Aug. 29, 2001
`
`PCT/P01/07434
`(86) PCT No.:
`(30)
`Foreign Application Priority Data
`
`Oct. 12, 2000 (JP)...................................... 2000-311626
`
`Publication Classification
`
`(51) Int. Cl." .................................................... HO1M 10/40
`(52) U.S. Cl. ........................... 429/326; 429/331; 429/338
`
`ABSTRACT
`(57)
`In a rechargeable non-aqueous electrolyte Secondary battery
`using positive electrodes, negative electrodes and a non
`aqueous electrolytic Solution, additives to the electrolytic
`Solution are used in combination, preferably in combination
`of at least two compounds Selected from O-terphenyl, triph
`enylene, cyclohexylbenzene and biphenyl, and thus there are
`provided batteries excellent in Safety and Storage character
`istics.
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`Patent Application Publication
`
`Jun. 26, 2003
`
`US 2003/0118912 A1
`
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`US 2003/0118912 A1
`
`Jun. 26, 2003
`
`ELECTROLYTIC SOLUTION FOR NON-AQUEOUS
`TYPE BATTERY AND NON-AQUEOUS TYPE
`SECONDARY BATTERY
`
`TECHNICAL FIELD
`0001. The present invention relates to a non-aqueous
`electrolytic Solution which can ensure Safety of batteries at
`the time of overcharging with improving recovery charac
`teristics of the batteries after Storage at high temperatures,
`and to a non-aqueous type Secondary battery using Said
`electrolytic Solution.
`
`BACKGROUND ART
`0002 Recently, AV devices and electronic devices such
`as personal computers of portable or cordless type have been
`rapidly developed, and Secondary batteries which are Small
`in size, light in weight and high in energy density are
`earnestly demanded as electric Sources for driving these
`devices. Among them, non-aqueous electrolytic Solution
`Secondary batteries using a negative electrode containing
`lithium as an active material are hopefully expected as
`batteries having high Voltage and high energy density.
`0003. In the above batteries, lithium-containing metal
`oxides which show a voltage on the order of 4V are used for
`positive electrode active materials, and materials capable of
`intercalation or deintercalation of lithium, Such as carbon
`aceous materials, are used for negative electrodes.
`0004 One of the most important tasks in these non
`aqueous electrolytic Solution batteries is to ensure the Safety.
`0005 Particularly, in lithium ion secondary batteries,
`when they are charged in excess of a given charging Voltage
`due to, for example, troubles of charging control circuits,
`they are in overcharged State, and lithium ions in the positive
`electrode are excessively extracted and migrate to negative
`electrode to cause absorption of lithium in an amount larger
`than the prescribed design capacity in the negative electrode
`or to cause precipitation of lithium as metallic lithium on the
`Surface of negative electrode. If the batteries in Such a State
`are further forcedly charged, internal resistance of the bat
`teries increases and generation of heat due to the Joule's heat
`becomes great to cause abnormal heat generation, and, in the
`Worst case, to result in thermal runaway. By providing a
`current interrupting Switch of temperature Sensing type (for
`example, a positive temperature coefficient thermistor (PTC)
`or a temperature fuse) outside the batteries, the current is
`interrupted without fail, and Safety can be ensured at the
`time of generation of abnormal heat. Furthermore, in order
`to Solve the problem of Overcharge, a means of interrupting
`the charging current upon Sensing the change of internal
`preSSure of batteries is generally employed as disclosed in
`U.S. Pat. No. 4,943,497.
`0006. However, in the case of using such a mechanical
`current interrupting mechanism, reduction of cost is difficult
`and, furthermore, with the batteries becoming Smaller and
`thinner, it becomes Structurally difficult to insert the mecha
`nism in the batteries.
`0007 For solving the above problems, there is proposed
`a method of adding to the electrolytic Solution an additive
`which causes a reversible redox reaction, thereby to Self
`consume the electric energy introduced into the batteries as
`
`a redox shuttle (for example, JP-A-1-206571, JP-A-6-
`338347, JP-A-7-302614, etc.).
`0008 However, in the method of using the redox shuttle,
`when the overcharging current becomes great, there are
`limits in charge transfer reaction rate and lithium ion transfer
`rate, and, thus, it cannot be Said that the method provides a
`Sufficient Safety.
`0009 For solving the above problems, JP-9-50822, JP-A-
`10-50342, JP-9-106835, JP-10-321258, Japanese Patent No.
`2939469, and JP-A-2000-58117 propose a means of adding
`to batteries an aromatic compound having a methoxy group
`and a halogen group, biphenyl or thiophene, or an aromatic
`ether compound, which polymerizes at the time of over
`charging to result in rising of temperature and, thus, to
`ensure the Safety.
`
`DISCLOSURE OF INVENTION
`0010. In the case of the batteries in which a current
`interrupting Switch of temperature Sensing type (for
`example, a positive temperature coefficient thermistor (PTC)
`or a temperature fuse) is provided outside the batteries
`against abnormal heat generation, when an excessively large
`overcharging current (5-6 C) of more than 5-6 times the
`rated capacity passes, the device perse generates heat due to
`the current and resistance increases, thereby interrupting the
`current, and thus the Safety can be ensured, but in the case
`of a current generally used for charging and discharging the
`batteries (less than 1-2 C at the maximum), the rising of
`temperature is insufficient and the resistance does not
`increase. When overcharging is carried out at Such a current
`value, the Safety cannot be Sufficiently ensured. If the Setting
`is made So that the resistance increases in the generally used
`current region, naturally the inherent performance of the
`batteries are damaged.
`0011. In the case of adding to the batteries the above
`mentioned additives Such as aromatic compound having a
`methoxy group and a halogen group, biphenyl or thiophene,
`and an aromatic ether compound, it has been confirmed that
`in the generally used current ranges, the additives polymer
`ize on the electrodes in overcharged State, and the Safety is
`improved.
`0012 However, it has been found that these additives
`must be added in an amount of not less than 1% by weight
`for ensuring the Safety at the time of overcharging, but if the
`additives are added in a large amount, in an Shelf life test, for
`example, an environment test (80 C.) which Supposes the
`case of leaving them in a car in Summer, these additives
`partially react to cover the active material, resulting in
`considerable deterioration of the battery characteristics.
`0013 The above phenomenon is considered to occur
`because oxidative polymerization potential of the additives
`lowers due to exposure of the battery to a high temperature
`environment, and, furthermore, the potential distribution in
`the charged electrode is not uniform and higher potential
`portions are partially present, and, as a result, the additives
`react even in the ordinary environment of potential at which
`battery is used.
`0014. The above problem of deterioration due to storage
`can be Solved, for example, by using an additive high in
`oxidative polymerization starting potential (for example,
`cyclohexylbenzene), but in this case, since the reaction
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`
`potential of the additive is rather high at the time of the
`overcharging, the Safety of overcharging cannot Sufficiently
`be ensured.
`0.015 The present invention solves the above problems
`and to provide a battery excellent in high-temperature Stor
`age characteristics while ensuring the Safety at overcharg
`ing.
`0016. In order to solve the above problems, according to
`the present invention, in a non-aqueous electrolytic Solution
`in which an electrolyte is dissolved in a non-aqueous Sol
`vent, two or more organic compounds differing in oxidative
`polymerization reaction potential are added. Preferably,
`organic compounds of relatively low oxidation reaction
`potential are added in a very Small amount, preferably not
`less than 0.01% by weight and less than 1.0% by weight
`based on the total amount of the electrolytic Solution,
`thereby to control the recovery characteristics after Storage
`and the Safety during overcharging. Specifically, it is pre
`ferred to add at least two organic compounds Selected from
`o-terphenyl, triphenylene, cyclohexylbenzene and biphenyl.
`0.017. It is preferred that not less than 1.0% by weight and
`not more than 3.0% by weight of o-terphenyl and not less
`than 0.01% by weight and less than 1.0% by weight of
`triphenylene are contained in the non-aqueous Solvent.
`0.018
`Furthermore, it is preferred that not less than 1.0%
`by weight and not more than 5.0% by weight of cyclohexy
`lbenzene and not less than 0.01% by weight and less than
`1.0% by weight of biphenyl are contained in the non
`aqueous Solvent.
`0019 Moreover, it is preferred that not less than 1.0% by
`weight and not more than 5.0% by weight of cyclohexyl
`benzene and not less than 0.01% by weight and less than
`1.0% by weight of o-terphenyl are contained in the non
`aqueous Solvent.
`0020) Further, it is preferred that not less than 1.0% by
`weight and not more than 5.0% by weight of cyclohexyl
`benzene, not less than 0.01% by weight and less than 1.0%
`by weight of o-terphenyl and not less than 0.01% by weight
`and less than 1.0% by weight of biphenyl are contained in
`the non-aqueous Solvent.
`0021
`Furthermore, it is preferred that all of o-terphenyl,
`triphenylene, cyclohexylbenzene and biphenyl are contained
`in the non-aqueous Solvent and the total amount of them is
`0.4-5% by weight based on the non-aqueous solvent.
`0022. These organic compounds are particularly effective
`when the positive electrodes comprise a material containing
`a lithium-containing metal oxide and the negative electrodes
`comprise a material containing graphite, and the non-aque
`ous electrolytic Solution exerts the higher effect when it is an
`electrolytic Solution in which a lithium Salt as a Solute is
`dissolved in a non-aqueous Solvent mainly composed of a
`cyclic carbonate and a chain carbonate.
`0023 The cyclic carbonate is preferably at least one
`compound Selected from ethylene carbonate (EC), propy
`lene carbonate (PC), butylene carbonate (BC) and vinylene
`carbonate (VC).
`0024. The chain carbonate is preferably at least one
`compound selected from dimethylcarbonate (DMC), diethyl
`
`carbonate (DEC), ethylmethyl carbonate (EMC), methyl
`propyl carbonate (MPC) and ethylpropyl carbonate (EPC).
`BRIEF DESCRIPTION OF DRAWING
`0025 FIG. 1 is a longitudinal sectional view of a cylin
`drical battery in the examples of the present invention and in
`the comparative examples.
`
`BEST MODE FOR CARRYING OUT THE
`INVENTION
`0026. In the present invention, recovery characteristics
`after Storage and Safety during overcharging can be con
`trolled by adding two or more organic compounds differing
`in oxidative polymerization reaction potential to the elec
`trolytic Solution.
`0027 Examples of organic compounds differing in oxi
`dative polymerization potential contained in the electrolytic
`Solution for non-aqueous type batteries in which an electro
`lyte is dissolved in a non-aqueous Solvent are o-terphenyl,
`triphenylene, cyclohexylbenzene and biphenyl. AS to the
`content of the organic compounds, the weight of the organic
`compound of relatively higher oxidative polymerization
`potential is preferably not less than 1.0% by weight and not
`more than 5.0% by weight based on the total amount of the
`non-aqueous electrolytic Solution. The weight of the organic
`compound of relatively lower oxidative polymerization
`potential is preferably not less than 0.01% by weight and
`less than 1.0% by weight based on the total amount of the
`non-aqueous electrolytic Solution. Furthermore, the weight
`ratio of the organic compound of relatively higher oxidative
`polymerization reaction potential and the organic compound
`of relatively lower oxidative polymerization reaction poten
`tial is preferably not lower than 20:1 and not higher than 2:1,
`more preferably not lower than 10:1 and not higher than 4:1.
`0028. In order to improve the recovery characteristics
`after Storage, the amount of the organic compound of
`relatively lower oxidative polymerization Starting potential
`(for example, biphenyl) is preferably Smaller, but in order to
`ensure the Safety at Overcharging, the organic compound
`must react as much as possible at Overcharging, namely, the
`amount is preferably rather larger.
`0029. According to the present invention, two or more
`organic compounds differing in oxidative polymerization
`reaction potential (hereinafter Sometimes referred to as
`“additives”) are used, and the amount of the organic com
`pound of relatively lower oxidative polymerization Starting
`potential (for example, biphenyl) is conspicuously reduced
`in this System, thereby maintaining excellent Storage char
`acteristics, and on the other hand the organic compounds
`react only Slightly at the overcharging, whereby polarization
`at the overcharging increases, and the organic compound of
`relatively higher oxidative polymerization Starting potential
`(for example, cyclohexylbenzene) react at an early stage,
`and thus the Safety can be ensured. As a result, there can be
`attained both the recovery properties after Storage and the
`insurance of Safety at Overcharging, which cannot be
`attained with addition of each organic compound Singly.
`0030 Since the additives in the present invention do not
`aim at an action as redox shuttles, the oxidation reaction is
`desirably irreversible and they differ in purpose from JP-A-
`7-302614 and JP-A-9-50822 which aim at reversibility of
`redox reaction.
`
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`0031. As the lithium-containing composite oxides used
`as positive electrode active materials in the present inven
`tion, mention may be made of, for example, Li CoO,
`LiNiO, (U.S. Pat. No. 4,302.518), Li MnO, LiCo, NiO,
`(JP-A-63-299056), Li Co.V.O., LiNiMO (M=Ti, V.
`Mn, Fe), Li Co, NiMO (M=Ti, Mn, Al, Mg, Fe, Zr),
`LiMnO, Li MiniMO (M=Na, Mg, Sc, Y, Fe, Co,
`Ni, Ti, Zr, Cu, Zn, Al, Pb, Sb) (x=0-1.2, y=0-1.0, f=0.9-0.98,
`Z=1.9-2.3, a+b+c-1.0, 0s as 1,0sbs 1,0sc-1). The value
`X is a value before Starting of charging and discharging,
`which increases or decreases by charging and discharging.
`0.032 The lithium-containing composite oxides used as
`positive electrode active materials in the present invention
`can be prepared by mixing carbonate, nitrate, oxide or
`hydroxide of lithium with carbonate, nitrate, oxide or
`hydroxide of a transition metal Such as cobalt, manganese or
`nickel at a desired composition, grinding the mixture and
`firing the powder or by a Solution reaction. The firing
`method is especially preferred, and the firing temperature
`can be 250-1500 C. at which a part of the mixed compound
`is decomposed and molten. The firing time is preferably
`1-80 hours. The firing gas atmosphere can be any of air
`atmosphere, oxidizing atmosphere or reducing atmosphere,
`and has no special limitation.
`0033. In the present invention, a plurality of different
`positive electrode active materials may be used in combi
`nation.
`0034. As current collectors of positive electrodes, there
`may be used any electron conductors as long as they do not
`undergo chemical changes in the constructed batteries. For
`examples, as materials of the current collectors, there may
`be used Stainless Steel, aluminum, titanium and carbon, and
`aluminum or aluminum alloys are especially preferred. AS
`for the shape of the current collectors, they may be in the
`form of foil, film, sheet, net, punched material, lath, porous
`material, foamed material, fiber group, shaped nonwoven
`fabric, and the like. The surface of the current collectors may
`be made rough by a Surface treatment. Thickness thereof is
`not particularly limited, and those of 1-500 um are used.
`0035. The negative electrode materials used in the
`present invention may be lithium alloys, alloys, intermetallic
`compounds, carbons, organic compounds, inorganic com
`pounds, metal complexes and organic high molecular com
`pounds, which are capable of absorbing and releasing
`lithium ions. These may be used each alone or in combina
`tion.
`0036) As the carbonaceous materials, mention may be
`made of, for example, cokes, pyrolytic carbons, natural
`graphite, artificial graphite, mesocarbon microbeads, graphi
`tized mesophase spherules, vapor deposited carbons, glassy
`carbons, carbon fibers (polyacrylonitrile fibers, pitch fibers,
`cellulose fibers and vapor deposited carbon fibers), amor
`phous carbons, and carbons prepared by firing organic
`materials. These may be used each alone or in combination.
`Among them, preferred are graphite materials. Such as those
`obtained by graphitizing mesophase Spherules, natural
`graphite and artificial graphite. These negative electrode
`materials may be used as composites, and, for example,
`combinations of carbon with alloys, carbon with inorganic
`compounds, and the like can be considered.
`0037. In the present invention, since Li is contained in the
`positive electrode active material, negative electrode mate
`rials which do not contain Li (Such as carbon) can be used.
`Moreover, when Li is added to Such negative electrode
`
`materials which do not contain Li in a small amount (about
`0.01-10 parts by weight based on 100 parts by weight of the
`negative electrode materials), even if the materials become
`inactive owing to the reaction of a part of Li with electrolyte,
`Li can be Supplemented with Li contained in the negative
`electrode materials, which is preferred. Li can be contained
`in the negative electrode materials, for example, in the
`following manner. That is, lithium metal which is molten by
`heating is coated on a current collector to which a negative
`electrode material is pressed, thereby impregnating the
`negative electrode material with Li, or lithium metal is
`previously applied to electrode group by press bonding and
`Li is electrochemically doped in the negative electrode
`material in the electrolytic Solution.
`0038. As current collectors of negative electrodes, there
`may be used any electron conductors as long as they do not
`undergo chemical changes in the constructed batteries. For
`example, as materials of the collectors, there may be used
`Stainless Steel, nickel, copper, titanium, etc. Copper or
`copper alloys are especially preferred.
`0039. As for the shape of the current collectors, they may
`be in the form of foil, film, sheet, net, punched material, lath,
`porous material, foamed material, fiber group, shaped non
`woven fabric, and the like. Moreover, the Surface of the
`current collectors may be made rough by a Surface treat
`ment. ThickneSS is not particularly limited, and those of
`1-500 um are used.
`0040. The non-aqueous electrolytic solution in the
`present invention comprises a Solvent and a lithium Salt
`dissolved in the Solvent. AS the non-aqueous Solvents,
`mention may be made of cyclic carbonates Such as ethylene
`carbonate (EC), propylene carbonate (PC), butylene carbon
`ate (BC) and vinylene carbonate (VC), non-cyclic carbon
`ates such as dimethyl carbonate (DMC), diethyl carbonate
`(DEC), ethylmethyl carbonate (EMC), ethylpropyl carbon
`ate (EPC), methylpropyl carbonate (MPC), methylisopropyl
`carbonate (MIPC) and dipropyl carbonate (DPC), aliphatic
`carboxylic acid esterS Such as methyl formate, methyl
`acetate, methyl propionate and ethyl propionate, Y-lactones
`Such as Y-butyrolactone, non-cyclic etherS Such as 1,2-
`dimethoxyethane (DME), 1,2-diethoxyethane (DEE) and
`ethoxymethoxyethane (EME), cyclic etherS Such as tetrahy
`drofuran and 2-methyltetrahydrofuran, dimethyl sulfoxide,
`1,3-dioxolan, alkyl phosphate esterS Such as trimethyl phos
`phate, triethyl phosphate and trioctyl phosphate, and fluo
`rides of them. These may be used each alone or in admixture
`of two or more. Among them, it is preferred to use a mixed
`System of a cyclic carbonate and a non-cyclic carbonate or
`a mixed System of a cyclic carbonate, non-cyclic carbonate
`and an aliphatic carboxylic acid ester as a main component.
`0041. The lithium salts which are dissolved in these
`solvents include, for example, LiCIO, LiBF, LiPF,
`LiAlCl, LiSbF, LiSCN, LiCl, LiCFSO, LiCFCO,
`LiASF, LiN(CFSO), Li BioCo (JP-A-57-74974),
`LiN(CFSO), LiPF (CF), LiPF (CF), etc. These
`may be contained each alone or in combination of two or
`more in the electrolytic Solution, etc. Among them, it is
`especially preferred that the Solution contains LiPF.
`0042 Especially preferable non-aqueous electrolytic
`Solution in the present invention is one which contains at
`least ethylene carbonate and ethylmethyl carbonate and
`LiPF, as a lithium salt. The amount of the electrolytic
`Solution contained in the battery is not particularly limited,
`and it can be used in a necessary amount depending on the
`amount of positive electrode active material and that of
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`
`negative electrode material and the Size of the battery. The
`amount of the lithium Salt dissolved in the non-aqueous
`solvent is not particularly limited, but is preferably 0.2-2
`mol/l, especially preferably 0.5-1.5 mol/l.
`0043. The electrolytic solution is ordinarily used by
`impregnating or filling a separator Such as of porous poly
`mer or nonwoven fabric with the electrolytic solution.
`0044) Moreover, there may be used a gelled electrolyte
`comprising an organic Solid electrolyte containing the non
`aqueous electrolytic Solution. AS the organic Solid electro
`lyte, polymeric matrix materials Such as polyethylene oxide,
`polypropylene oxide, polyvinylidene fluoride and deriva
`tives, mixtures and composites of these materials are effec
`tive. Especially preferred are copolymers of vinylidene
`fluoride and hexafluoropropylene and mixtures of polyvi
`nylidene fluoride and polyethylene oxide.
`0.045. As the separator, an insulating microporous thin
`film having a high ion permeability and a desired mechani
`cal Strength is used. The Separator preferably has a function
`of closing the pores at a temperature of 80 C. or higher to
`enhance the resistance. Sheets or nonwoven fabrics made
`from olefin polymers comprising one or combination of
`polypropylene and polyethylene or glass fibers are used
`from the points of organic Solvent resistance and hydropho
`bic properties. Pore diameter of the Separator is preferably in
`Such a range that active materials, binders and conducting
`agents which are released from the electrode Sheets do not
`permeate through the pores, and, for example, the pore
`diameter is preferably 0.01-1 um. The thickness of the
`Separator is generally 5-300 um. The porosity is determined
`depending on the permeability to electron or ion, kind of
`materials or film thickness, and is desirably 30-80%.
`0046) The shape of batteries can be any of sheet type,
`cylinder type, flat type, rectangular type, etc. When the
`shape of batteries is sheet type, cylinder type or rectangular
`type, the mix of positive electrode active material or nega
`tive electrode material is used mainly by coating on a current
`collector, then drying and compressing the collector.
`0047 The shape of the rolled electrodes in the present
`invention is not necessarily in the form of true cylinder, and
`may be in the form of ellipsoidal cylinder having a ellip
`Soidal Section or in the form of Square pillar Such as
`rectangle.
`0.048
`Preferred combinations in the present invention are
`combinations of the preferred chemical materials and the
`preferred battery constituting parts mentioned above. Espe
`cially preferred are those which contain Li CoO, LiNiO,
`LiMn2O (OsXs 1) as positive electrode active materials,
`and acetylene black as a conducting agent. The current
`collector of positive electrode is made of Stainless Steel or
`aluminum, and is in the form of net, sheet, foil or lath. The
`negative electrode material preferably contains at least one
`compound Such as alloy and carbonaceous material. The
`current collector of negative electrode is made of StainleSS
`Steel or copper and is in the form of net, sheet, foil or lath.
`Carbon materials. Such as acetylene black and graphite as the
`electron conducting agent may be contained in the mix used
`together with positive electrode active materials or negative
`electrode materials. AS the binders, there may be used
`fluorine-containing thermoplastic compounds Such as poly
`Vinylidene fluoride and polytetrafluoroethylene, polymers
`containing acrylic acid, and elastomerS Such as Styrene
`butadiene rubber and ethylene-propylene terpolymer each
`
`alone or in admixture. The electrolytic Solution preferably
`contains cyclic or non-cyclic carbonates Such as ethylene
`carbonate, diethyl carbonate, dimethyl carbonate and ethyl
`methyl carbonate or additionally aliphatic carboxylic acid
`esterS Such as methyl acetate and methyl propionate, and
`LiPF, as a lithium salt. The separator preferably comprises
`polypropylene or polyethylene each alone or in combina
`tion. The battery may have any shapes. Such as cylindrical
`shape, flat shape, and rectangular shape. The battery pref
`erably has a means for ensuring Safety against errors in
`working (e.g., an internal pressure releasing type Safety
`Valve, a separator which enhances resistance at high tem
`peratures).
`
`EXAMPLES
`0049. Examples of the present invention will be
`explained below referring to the drawing.
`
`Example 1
`0050 FIG. 1 is a longitudinal sectional view of the
`cylindrical battery used in this example. In FIG. 1, the
`reference numeral 1 indicates a battery case made by work
`ing a stainless Steel plate having resistance to organic
`electrolytic Solution, 2 indicates a Sealing plate provided
`with a Safety valve, 3 indicates an insulation packing, 4
`indicates an electrode plate group, and positive electrode and
`negative electrode with Separator interposed between the
`positive electrode and the negative electrode are rolled a
`plurality of times into a spiral form and inserted in the case
`1. A positive electrode lead 5 is drawn from the positive
`electrode and connected to the Sealing plate 2, and a negative
`electrode lead 6 is drawn from the negative electrode and
`connected to the bottom of the battery case 1. The reference
`numeral 7 indicates an insulation ring, which is provided at
`the upper and lower portions of the electrode plate group 4.
`The positive electrode, the negative electrode, and others
`will be explained in detail below.
`0051. The positive electrode was made in the following
`manner. LiCO and Co-O were mixed and fired at 900 C.
`for 10 hours to prepare an LiCoO powder. This powder was
`mixed with 3% of acetylene black and 7% of a fluorocarbon
`polymer binder based on the weight of the LiCoO powder,
`followed by Suspending the mixture in an aqueous car
`boxymethyl cellulose Solution to prepare a positive electrode
`mix paste. The resulting positive electrode mix paste was
`coated on the Surface of an aluminum foil of 20 um in
`thickness which was a positive electrode current collector,
`and the coat was dried, followed by rolling to make a
`positive electrode plate of 0.18 mm in thickness, 37 mm in
`width and 390 mm in length.
`0052 For the negative electrode, a mesophase spherule
`which was graphitized at a high temperature of 2800 C.
`(hereinafter referred to as “mesophase graphite') was used.
`This mesophase graphite was mixed with 3% of a Styrene
`butadiene rubber based on the weight of the mesophase
`graphite, and then the mixture was Suspended in an aqueous
`carboxymethyl cellulose Solution to prepare a paste. This
`negative electrode mix paste was coated on both sides of a
`Cu foil of 0.02 mm in thickness and dried, followed by
`rolling to make a negative electrode plate of 0.20 mm in
`thickness, 39 mm in width and 420 mm in length.
`
`Samsung Ex. 1019, Page 6 of 10
`Samsung Electronics Co., Ltd. v. RJ Technology, LLC
`IPR2023-01183
`
`

`

`US 2003/0118912 A1
`
`Jun. 26, 2003
`
`0.053 A lead made of aluminum was attached to the
`positive electrode plate and a lead made of nickel was
`attached to the negative electrode plate, and the positive
`electrode plate and the negative electrode plate with a
`polyethylene separator of 0.018 mm in thickness, 45 mm in
`width and 840 mm in length interposed between the positive
`electrode plate and the negative electrode plate were rolled
`into a spiral form and inserted in a battery case of 17.0 mm
`in diameter and 50.0 mm in height. The electrolytic solution
`used was prepared by dissolving 1 mol/liter of LiPF in a
`mixed solvent comprising EC and EMC at a volume ratio of
`30:70, and as additives, 2% by weight of o-terphenyl and
`0.2% by weight of triphenylene based on the total amount of
`the electrolytic solution were added to the electrolytic solu
`tion. The electrolytic solution was poured into the battery
`case, and then the case was Sealed to make a battery 1
`(battery capacity: 800 mAh) of the present invention.
`Example 2
`Acylindrical battery of spiral type was made in the
`0.054
`Same manner as in Example 1, except that cyclohexylben
`Zene in an amount of 2% by weight and biphenyl in an
`amount of 0.2% by weight based on the total amount of the
`electrolytic Solution were used as the additives to the elec
`trolytic solution. The thus obtained battery was referred to as
`battery 2 of the present invention.
`Example 3
`Acylindrical battery of spiral type was made in the
`0.055
`same manner as in Example 1, except that cyclohexylben
`Zene in an amount of 2% by weight and O-terphenyl in an
`amount of 0.2% by weight based on the total amount of the
`electrolytic Solution were used as the additives to the elec
`trolytic solution. The thus obtained battery was referred to as
`battery 3 of the present invention.
`Example 4
`0056. A cylindrical battery of spiral type was made in the
`Same manner as in Example 1, except that cyclohexylben
`Zene in an amount of 2% by weight, biphenyl in an amount
`of 0.2% by weight and o-terphenyl in an amount of 0.2% by
`weight based on the total amount of the electrolytic Solution
`were used as the additives to the electrolytic solution. The
`thus obtained battery was referred to as battery 4 of the
`present invention.
`
`Example.5
`0057. A cylindrical battery of spiral type was made in the
`Same manner as in Example 1, except that cyclohexylben
`Zene in an amount of 2% by weight, biphenyl in an amount
`of 0.2% by weight, o-terphenyl in an amount of 0.2% by
`weight and triphenylene in an amount of 0.1% by weight
`based on the total amount of the electrolytic Solution were
`used as the additives to the electrolytic solution. The thus
`obtained battery was referred to as battery 5 of the present
`invention.
`
`Comparative Example 1
`Acylindrical battery was made in the same manner
`0.058
`as in Example 1, except that the additives to the electrolytic
`solution were not used. The thus obtained battery was
`referred to as a comparative battery (battery 6).
`
`Comparative Example 2
`0059 A cylindrical battery of spiral type was made in the
`Same manner as in Example 1, exc