TW447165B - Nitrite additives for nonaqueous electrolyte rechargeable electrochemical cells - Google Patents

Abstract

A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one nitrite additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is an alkyl nitrite compound.

Description

447165 V. Description of the invention (1) Cross-reference to related applications This application claims the priority based on the US Pro Serial No. 6 0/1 1 7, 1 04, which was filed on January 25, 999. Background of the invention The present invention relates generally to an electrochemical battery, and more particularly, to a rechargeable clock ion battery. More particularly, the present invention relates to a chain ion battery, with additives. The electrolyte is used to activate, and the provided additives are used to achieve high charge / discharge power, long cycle / person 'to minimize the irreversible ability of the first cycle. According to the present report: The preferred additive for chemical degradation and degradation is a nitrite compound. Lithium-ion rechargeable batteries generally include a carbon red ^% Λ cathode electrode and a lithiated anode electrode. Because in the fully charged lithium ion 畲% + a 口 你 疋 王 το electricity ~ carved 卞 in the pool, the potential of the anode material [for UhCoO〗, is as high as 4.3 volts (v) For Li / Li +), and the low potential of carbonaceous cathode materials (for graphite, 0.00 volts for Li / LP), 'the choice of electrolyte solvent system is limited: Lithium anode materials used in general have high oxidative stability, and have good dynamic stability to carbonaceous cathode materials. They are usually used in lithium ion and cell electrolytes. · In order to achieve the best battery performance (high-speed capability and long cycle life) 'Commonly used in commercial batteries include cyclic carbonate (high dielectric constant solvent)' and linear carbonate (low viscosity solvent) ) Of the solvent system of the mixture. Carbonate-based electrolyte batteries are known to deliver more than 1,000 charge / discharge cycles at room temperature. U.S. Patent Application Serial No. 0 9/1 33, 799, 'is issued to the awardee of the present invention and It is hereby incorporated herein by reference for the activation of lithium ion batteries

447165 5. Description of the invention (2) The electrolyte is a quaternary mixture of organic carbonate solvents, which can be discharged at a temperature below -20 ° C, and shows good cycle characteristics at temperatures as low as -40 ° C. The quaternary solvent system includes ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl ethyl carbonate (EMC), and diethyl carbonate (DEC). The design of lithium-ion batteries usually involves an area The necessary improvement, while interrelated with the other, depends on the target battery application. Charge at Killer [1.0 Molar concentration of LiPF6 / EC_. DMC: EMC-_DEC = 45-.22 ', 24 · 8_ · 8.2, approximately 65 milliamps (mAh) / gram, against 1.0 MoPF concentration of LiPF6 / EC: DMO3 0: 70: about 35 milliamps / gram] during the period of sacrifice to increase the irreversible capacity of the first cycle, and achieve a lithium-ion battery capable of cycling at low temperatures. Use the above-mentioned quaternary solvent electrolyte. To replace the commonly used binary solvent electrolyte (such as: 1.0 Molar concentration of LiPF6 / EC: DMC = 3 0:70 vol / vol: it freezes at -11 ° C) Getting 'Because of the irreversible ability of this first cycle, lithium-ion batteries usually have limited anodes. Because all lithium ions, which are derived from a lithiated anode, go back and forth between the cathode and the anode during charging and discharging, the greater the irreversible capacity in the first cycle: the lower the battery capacity in the subsequent cycle, and The lower the efficiency of the battery. Therefore, it is desirable to minimize, or even exclude, the first-cycle irreversible capability in a lithium-ion battery while maintaining the low-temperature cycling capability of the battery. According to the present invention, these objects are achieved by providing an organic nitrite in a quaternary solvent electrolyte. Lithium-ion batteries activated with these electrolytes show a lower first-cycle irreversible capacity than the same quaternary solvent electrolyte-activated batteries lacking the ASUS acid and vinegar additive. The result is "includes

447165 V. Description of the invention (3) Batteries with nitrite additives have higher follow-up cycle capability than batteries in the control group. The cycle capacity of the battery of the present invention at room temperature, ′ and at low temperature, ie, as low as about -40 C, is as good as a battery activated with a quaternary solvent electrolyte lacking a schist acid additive. The abstract of the present invention is generally known: when a lithium ion battery constructed with a carbon cathode is initially charged with a potential under discharge conditions to charge the battery, it will result from the formation of a passive film on the cathode surface, There are some permanent loss of capacity. This permanent loss of ability is called the first cycle irreversible ability r However: The process of film formation is highly dependent on the reactivity of the electrolyte components at the battery charge potential. The electrochemical properties of the pure thin film also depend on the chemical composition of the surface film. The formation of surface films is inevitable for metal detection systems, and especially for clock metal cathodes and carbon cathodes inserted by clocks, due to the relatively low potential and high reactivity of clocks for organic electrolytes. The ideal surface film is known as the solid-electrolyte interface phase (SEI) and must be electrically insulating and ion-conducting. When most of the metal inspection, and especially the lithium electrochemical system meets the first requirement, it is difficult to meet the second requirement: the resistance of these films can not be ignored and the result is that the impedance is caused by the formation of the surface layer Accumulation in the battery 丨 This surface layer is formed during the charging and discharging of the lithium ion battery, causing unacceptable polarization. On the other hand, if the SEI film is conductive, & electrolyte decomposition reaction on the cathode surface: it will not stop due to the low potential of the lithiated carbon electrode. Therefore, the composition of the electrolyte has a significant impact on the discharge efficiency of the metal detection system, and especially the loss of permanent capacity in the battery. example

Page 6 447165 V. Description of the invention (4) For example: when using LiPFs / EC: DM〇3〇: 70, which has a concentration of 1.0 mol, to activate the internal battery, the irreversible capacity of the first cycle is about 35 mA / Grams of stone black. However, under the same cycle conditions, when 1.0 moles of

LiPF6 / EC: DMC: EMC: DEC = 4 5: 22: 24.8: 8.2 When electrolytic f was used, the irreversible capacity of the first cycle was found to be 65 mA / g of graphite. Furthermore, a lithium ion battery, which is a binary solvent electrolyte 1 of acetic acid and dimethyl acetic acid, cannot be circulated at a temperature lower than about -11 ° C. The quaternary solvent electrolyte of the previously-referenced patent application, which enables lithium-ion batteries to cycle at many low temperatures, 'is a compromise between the viewpoints of providing a wider use temperature and acceptable cycle efficiency. · Highly desirable is to maintain the advantages of lithium ion batteries that can operate at temperatures as low as about -40 ° C 丨 At the same time, the irreversible capacity of the first cycle is minimized. Adding acidic vinegar additives to the electrolyte to achieve: In addition, the present invention can summarize other non-aqueous organic organic electrolyte systems, such as: binary solvent and ternary solvent systems, and contains in addition to linear or cyclic carbonate Electrolyte system of the solvent of the mixture. For example: linear or cyclic ethers or esters can also be included as electrolyte groups. Although the real reason for the improvement observed is not clear, its hypothesis is: sub- bowl acid, the additive competes with the existing electrolyte components: reacts at the surface of the cathode during the initial lithiation: forms an I film with advantages. . Therefore, the SE I & 4 film is more insulating than the thin film formed without the nitrite additive, and the result is that the lithiated carbon electrode is better protected from other electrolytes. reaction? So get a lower number, the ability to cycle irreversibly.

Phantom page 447165 V. Description of the invention (5) '--- These and other objects of the present invention will gradually become more apparent to those skilled in the art with the following description and accompanying drawings. . …, A brief description of the diagram. Figure 1 is a graph showing the flattening ability of two sets of lithium ion batteries after ten cycles. One set is activated with a quaternary acid solvent mixture lacking a nitrite additive. Linic acid: Comparison of battery packs. Adding a detailed description of the preferred embodiment The electrochemical battery constructed according to the present invention includes a cathode active material selected from Group IA, ‘IIIA or IIIB of the periodic table of elements, including alkali metal lithium: sodium, potassium, and the like. What is the preferred cathode active material? In the electrochemical storage battery system, the cathode electrode contains a substance capable of inserting and removing the inserted metal, and the alkali metal is preferably lithium. Carbonaceous cathodes contain any carbon of the same form (for example: coke, graphite, acetylene black, carbon black, broken glassy carbon, etc.), 'The lithium species that can reversibly maintain is better. Graphite is particularly preferred because it is relatively high The ability of the carbon fiber to maintain: regardless of the form of carbon, carbon fiber is particularly superior. 'Because the fiber has particularly excellent mechanical properties, it allows it to be made into a sturdy electrode: able to endure repeated charging / discharging cycles. break down. 'Furthermore, the high surface area of carbon fibers allows fast charge / discharge rates' The preferred carbonaceous materials for use as cathodes in electrochemical batteries are described in U.S. Patent No. 1 issued to Taco House (Ding 31 ^ 11). No. 5,443,928, which is issued to the recipient of the present invention and is incorporated herein by reference. / General battery cathodes are made by mixing about 90 to 97 weight percent of graphite with about 3 to 10 weight percent of a binding substance.成。 The adhesive substance is

Page 844716 5 V. Description of the invention (6) Preferred are fluororesin powders, such as polytetrafluoroethylene (pTFE): polyvinylidene fluoride (PVDF), polytetrafluoroethylene (ETFE) ): Polyamide and polyimide,, and mixtures thereof. The electrode active mixture is provided on a current collector such as: nickel, stainless steel, or copper foil or mesh that has been cast, pressed, rolled, or otherwise contacted with the active mixture. The cathode component further has an extension bow or wire of the same material as the cathode current collector, that is, preferably nickel. In the case of the negative electrical configuration, the battery case is, for example, welded and welded to a conductive metal, Integratedly formed. • In addition, broken cathodes can be formed in some other shapes, such as: bobbin shape, cylindrical shape, or ingot shape, to allow another low surface battery design? The anode of the battery preferably contains a lithiated material that is stable in the air and easy to handle. Examples of such air-stabilized lithiation anode materials include: oxides of metals such as vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, and manganese, sulfides, Selenide and telluride ... Preferred oxides include: LiNi02, LiMn204, LiCo02, LiCoG92Sn " 02, and UC〇1 x Nix02. Before the electrode is made to be used in an electrochemical cell, the lithiated active material is preferably mixed with a conductive additive. Suitable conductive additives include acetylene black, carbon black, and / or graphite. When mixed with the above active materials, such as: nickel, aluminum, titanium, and stainless steel powder metal can also be used as conductive diluent: the electrode further contains a fluororesin binder 'preferably in the form of powder, Such as:? Is it? £.,? ? 〇?., £ 1 ^ £, .. polyamine and polyimide, and mixtures thereof, 0

Page 944716 5 Five 'invention description (7) In order to charge out the potential generated by this storage, and LixC6 electrode can be provided together to provide another storage material and active solid state copper oxide silver vanadium iron and The lithium carbon outside the fluorinated battery tends to reflect that the sexual electrodes of the present invention are free from the electrode pole and anode active and insoluble porous properties. . General partition. This situation is folded into an image when the electrode assembly (je 1 1 yr ο 1 1 of the battery is used to recharge the battery, and the battery is tested for metal.) Discharge, including electricity, the battery, to test the metal cathode, 'in the X range in the general manner of 1. The structure contains substances that are inserted together but not limited to titanium and oxidized substances. However, the problem is due to mutual ions. The anode is inserted into the carbonaceous cathode using the outside. The ions used saturate the carbon-containing cathode from the anode material via the electrolyte. The obtained and between 1. 〇. Then the battery and electricity are discharged. Before the cathode is added to the battery Into the carbon .. In this case, the anode body manganese dioxide, silver vanadium oxide, copper sulfide, iron sulfide, and disulfide. This method is related to the treatment when in contact with air, lithiation such as The internal electrical material in the physical compartment included in the copper battery is not included. In addition, the form of the electrical separator is allowed when the cathode and the curved structure are rolled or). A separator. · The separation force is short-circuited. · The reactive outer partition cell is electrified instead of flakes .. Many are placed and connected to each other in order to provide the cathode and the device are electrically insulating and the material of the separator is also · And the material of the electrolyte-free device has a certain period of electrolyte flow. It is placed in the outer shell of the cathode and anode in the middle of the cathode fold. It is received into a cylindrical "jelly roll anode." When it exceeds the anode plate of its electrode, or page 10, 447165 V. Description of the invention (8) The extension includes: from polyethylene terephthalate and polyfluorinated polymer fibers using diethylamine Fibrous fabric. It is used as a thin porous film alone. Other suitable materials, ceramics, commercial cloth, polypropylene, polyethylene, fiberglass, etc. are commercially available from Polytetrafluoroethylene film named Rentex UITEXH Kemper π A 〇emP last Inc.): Commercially known from the name CELGARD [celanese plastic c] (^ elanese Plastic c) 〇jnpany, Inc)] polypropylene film and Desi the industry name Glass (DEXIGLAS) [C, H. Durst sector (Dexter Div.), Durst company (Dextej_ c〇rp.)] Available from film. The choice of electrolyte solvent system for activating alkali metal electrochemical cells is very important, and especially for fully charged lithium-ion batteries, because of the high potential of the anode substance [up to 4.3 volts (V) for LifoC for Li / Li +) and the low potential of the cathode material (0.00 volts for graphite versus L i / L i +) for graphite. According to the present invention, a suitable non-aqueous electrolyte contains an inorganic salt 'dissolved in a non-aqueous solvent, and more preferably a metal test salt dissolved in a quaternary mixture of an organic carbonate solvent, the solvent comprising a dialkyl carbonate ( Non-cyclic), is selected from diethyl carbonate (DMC): diethyl carbonate (DEC), dipropyl carbonate (DPC)., Ethyl ethyl carbonate (EMC), methylpropyl carbonate (MPC) ,, Ethylene carbonate (EPC) and mixtures thereof, and at least one selected from the group consisting of propylene carbonate (PC), vinyl carbonate (EC), butene carbonate (BC) and carbenevinylene (VC) And cyclic carbonates thereof. Organic carbonates are commonly used in battery chemistry 'in electrolyte solvent systems because they show high oxidative stability to anode materials and good dynamic stability to cathode materials.

447165 V. Description of the invention (9) A preferred electrolyte according to the present invention comprises a solvent mixture of EC: DMC: EMC: DEC. The optimal volume percentage range of different carbonate solvents includes: the range of EC is about 10% to about 50%; the range of DMC is about 5% to about 75%: the range of EMC is about 5% to about 50% and DEC The range is about 3% to about 45%. The electrolyte containing this quaternary carbonate mixture shows a freezing point below -50, and the lithium ion battery activated by this mixture has very good cycling behavior at room temperature and very good at temperatures below ~ 20 aC. Discharge and charge / discharge cycle behavior ... Known lithium salts that can be used as a medium to transfer alkali metal ions from the cathode to the anode and back again include: LiPF6, LiBF4, LiAsF6, .LiSbF6.,

LiC104 ,, LUKl4, LiGaCl4, LiC (S02SF3) 3 > LiN03 ,, LiN (S02SF3) 2, LiSCN, Li03SCF2CF3, LiC6F5S03, U02CCF3, US03F, .LiB (C6H5) 4, LiCF (C6H5) 4, and LiCF3S03, and their proper concentration of salt A typical range is between about 0.8 and 1.5 moles. According to the present invention, at least one organic nitrite additive, preferably an alkyl nitrite compound, is provided as a co-solvent in the aforementioned alkali metal ion or an electrolyte solution in a rechargeable electrochemical cell. The nitrite additive is preferably an alkyl nitrite compound having the general formula (R0) N (= 0), which is an organic group of a saturated or unsaturated hydrocarbon, or a heteroatom-containing group containing 1 to A saturated or unsaturated organic group of 10 carbon atoms. The biggest effect was found in the use of methyl nitrite, ethyl nitrite, propyl nitrite, isopropyl nitrite: butyl nitrite, isobutyl nitrite When tertiary-butyl nitrite, benzyl nitrite and phenyl nitrite, and mixtures thereof are used as additives.

44716 5 • · 1 " " ** _ V. Description of the invention (10) The above compounds are intended to be used as examples for the present invention and are not to be construed as limiting. It will be easy for those skilled in the art to understand the acidic acid compounds from the general consumption range published above and according to the present invention, which are used as an electrolyte additive? In order to achieve high charging / discharging power, long cycle life and minimize the irreversible ability of the first cycle. When not intending to be limited by any special reaction mechanism, it is believed that due to the existence of the N = 0 bond in the nitrite functional group, there is a bond between oxygen and R, and the nitrite intermediate can effectively interact with other electrolytes The solvent or solute competes with the reacted and formed arsenite on the surface of the carbonaceous cathode, that is, the lithium salt of lithium nitrite or the reduction product of nitrite. The resulting SEI layer is more ionically conductive than a SEI layer formed without the organic nitrite additive. As a result, "The chemical composition and the possible form of the carbonaceous cathode surface protective layer. It is believed to be changed with the advantages of the battery cycle characteristics / the combination of the battery described herein." Curl requirements battery form. That is, the manufactured anode, cathode and separator are in the form of "杲; jellyroll n" or "wund element cell stack" in the form of Together '. So that the cathode is outside the roll, used to make electricity and the battery case in contact with the case in the negative state of the case. So that the appropriate top and bottom insulators, curling requirements battery stack is inserted into the appropriate size metal case? The metal case can include materials such as: non-mineral steel, soft steel, nickel-clad soft steel, titanium or aluminum, but is not limited to this, as long as the metal material is compatible with the battery components A metal dish-like body. It has a first hole for the sealing / terminal pin feeding channel for the metal to be broken, and is used as an electrolyte.

Page 13 447165 V. Description of the Invention (ii) '—the second hole filled. The glass used is a kind of anti-corrosion, and it has a stone content of about 50% by weight, such as: CABAL 12, TA 23, FUSITE 425 or FUSITE 435 .. The positive electric terminal needle feed, the channel preferably includes Qin ', although it is also possible to use flip, boat, brocade, stainless steel. > The top of the battery contains elements that are compatible with other components of the electrochemical battery, and are anti-corrosive. The anode vessel is welded to a positive terminal pin in a glass-to-metal seal, and the top is welded to the housing containing the electrode stack. The battery is then filled and hermetically sealed with an electrolyte solution containing at least one of the above-mentioned nitrite additives, such as a closed welded stainless steel ball over the filled hole, 'but not limited to this. The above combination summarizes the negatively charged battery case ', which is the preferred structure of the exemplary battery of the present invention. As is well known to those skilled in the art, the electrification system exemplified in the present invention can also be constructed in the form of a positive shell. The following example summarizes the manner and process of the electrochemical cell according to the present invention, and publishes the best form expected by the inventors to carry out the present invention, but it is not interpreted as a limitation.

Example I Five. Ion batteries were constructed as test media and the batteries were divided into two groups. A set of two batteries is activated with a quaternary carbonate solvent system electrolyte lacking a nitrite additive, while the remaining two batteries have the same electrolyte, but include a nitrite additive. The battery is the same except for the electrolyte. In particular, the anode was prepared by casting a LiCo02 anode mixture on a foil. The anode mix contains 91% by weight of LiCo02, 6% by weight of graphite additives, and 3% by weight of PVDF binder. The cathode is prepared by adding

Page 14 4471 6 5 V. Description of the invention (12) ---- 9 1. The cathode mixture of 7% by weight graphite and 8.3% by weight of the binder is bound to the copper alloy. "The structure of the electrode composition is to place a layer of a polyethylene separator between the anode and the cathode" and to curl the electrode spirally to fit into a stainless steel can of a certain size ". The battery was activated with an EC: DMC: EMC: DEC = 45: 22: 24.H 2 electrolyte having an LlPF column of 1.0 Molar concentration (group 丨) The battery of the second group made according to the present invention further had a ·· 〇5 Mol: Agro sound · ° Third-butylarylene vinegar (TBNI) is dissolved therein. Finally, the battery is grounded. & d is closed then all five batteries are cycled between 4.1 volts and 2 75 volts. The electrical cycle is performed at a constant current of 100 milliamps until the battery reaches full volts. Then, the charging cycle continues at 4.1 volts until 1 to 20 milliamps. After 5 minutes of rest, the battery was discharged to 2.75 volts at a current of 100,000 mA. · Before the next cycle; ^ 5 minutes. The average initial charge and discharge power of the two groups of batteries is summarized in Table 1. The irreversible capacity of the first cycle is calculated as the difference between the first charging force and the first discharge. . The first cycle capacity and irreversible capacity between electric power, the first charge, the first discharge irreversible group (milliamps) (milliamps) (milliamps) 1 641.4 ± 1.5 520.2 soil 9.5 1 2 1-2 ± 1 0.2. 5.3 547.0 ± 2.4 74.7 ± 7.7

Page 15 447 1 65_ V. Description of the invention ¢ 13) The data in Table 1 clearly shows that the two groups of batteries have similar first cycle charging power. However, the first cycle discharge force is quite different. The battery of group 2 activated with an electrolyte containing a third-butyl nitrite additive has a much higher first cycle discharge capacity (approximately 5.2%) than the battery of group 1 '. As a result, the second group of batteries also has a lower first-cycle irreversible capacity of about 38% than the first group of batteries.

Example I After the initial cycle, the cycle of five batteries was continued for a total of 10 times under the same cycle conditions as described in Example I. The discharge capacity and capacity maintenance of each cycle are summarized in Table 2. Capacity maintenance is defined as the percentage of discharge capacity per discharge cycle relative to the discharge capacity of the first cycle. Table 2 Cyclic discharge capacity and ability to maintain the number of cycles in group 1 and group 2 (milliamps) Maintenance (%) Capacity (milliamps) Maintenance (%) 1 520.2 100.0 547.0 100.0 2 510.2 98.1 542.0 99.1 3 503.4 96.8 536.9 98.1 4 497.6 95.7 532.1 97.3 5 493.2 94.8 528.2 96.6 6 489.4 94.1 524.6 95.9 7 486.1 93.4 521.7 95.4 8 483.2 92.9 5 18.7 94.8 9 480.2 92.3 516.3 94.4 10 478.2 91.9 513.9 93.9

Page 16 447165 V. Description of the invention (14) The data in Table 2 shows that with the addition of a third-butyl nitrite battery, it consistently shows a higher discharge energy in all cycles. <2 , This higher capacity is not depleted by the consumption of lower cycle life, and the two groups of batteries basically pass through different cycles? Has the same 苐 1 force to maintain. , J 衮 能

Example I I I After the above cycle test described in Example 11, the battery was charged according to the procedure of Example I. Then, the battery is discharged to 2.75 volts at the recovery of 100 milliamps, and then there is an open circuit for five minutes to discharge the constant current of 500 milliamps to 2_75 volts, and then There are five ^ 'continued with an open circuit break and continued with a constant current of 250 milliamps, and then there are five minutes of open circuit rest., And finally, with a constant current of 75 milliamps Discharge to 2. 7 5 volts, and then there are five or eight at 0 0 π minutes to put the circuit to rest at each discharge rate. The average total capacity of the open 0, v key; J ', and under different constant currents Compared with the average discharge efficiency (set, Table 100% capacity of discharge at a constant current) and the summary is shown in Table 3, the discharge capacity is the accumulation from one discharge current to the next. ’In Table 3 Discharge capacity at different currents (milliamps) Group 1000 milliamps 500 milliamps 250 milliamps 100 milliamps 1 277.8 43 9.8 459.8 465.9 2 262.2 479.0 499.9 505.8

447165

V. Description of the invention (15) Discharge efficiency (%) at different currents Group 100 mAh 500 mA 250 mA 100 mA 1 59 7 94 4 98.1 100.0 2 5 1 8 94 7 98.8 1 00.0 According to the data, the second group of batteries with a nitrite additive has an increased discharge capacity compared to the first battery at a discharge rate equal to or less than 500 milliamps (at a rate of about 1C). However, at a higher 2 electrical rate (100 mA., A rate of about 2C), the first control group battery has a higher ability to transmit than the second iris battery. The same trend is shown in Table 4. At a discharge current of 500 milliamps or less, the second group of batteries showed similar discharge efficiency to the first battery. At a higher discharge current (that is, 1000 milliamps), the battery of the first control group has a higher discharge efficiency than the battery of the second group. After the above discharge rate capability test, all the batteries were charged according to the procedure described in Example 1. Five test batteries were then stored for 13 days at 37 C on-circuit voltage (0 CV). Finally, discharge the battery and repeat the cycle eight times. -Calculate the% self-discharge and the capacity maintenance, and show it in Table 5. Table 5 Self-discharge rate and capacity maintenance after storage Group Self-discharge (%) Capacity maintenance (%)

Page 18 d4716 5 Five 'invention description (16) ------ The data in Table 5 shows that the two groups of batteries show similar self-discharge rate and similar capacity maintenance rate after storage. However, because the battery of the second group has a lower discharge capacity than the battery of the second group, although it shows a similar self-discharge and the force maintenance rate, the battery of the second group still has a higher capacity than the battery of the first group. f yields 20 cycles' and the results are summarized in FIG. In particular, the curve] is calculated from the average cycle data of the first group of batteries lacking the acetic acid additive, and the curve 12 is the average of the second group of batteries containing the third-butyl nitrite additive. By the architecture ... Increasing the discharge capacity after 20 cycles is clear. -In order to produce a reduction reaction of a non-conductive SEI layer containing a reduction product of a nitrite additive according to the present invention, the nitrite additive must effectively compete with the reaction of other electrolyte components on the cathode surface. In this regard, the R-0 bond in the nitrite additive having the general formula (R0) N (= 0) must be weak or reactive. This point has been described in U.S. Patent Application Serial No. 0 9/1 0 8, 1 43, which is issued to the recipient of the present invention and is hereby incorporated herein by reference. The description in this application: When a nitrite additive When having a relatively weak C-0 bond, such as the third-butyl sulfonate, for items with delayed voltage reduction and reduction of the growth of Rdc, can be observed in the oxidation chain / silver cell The excellent effect is based on similar reasons. It is believed that the same kind of nitrite additives that have advantages in the discharge performance of lithium primary electrochemical cells: due to the formation of a good SEI film on the surface of the carbon cathode, the first cycle of lithium ion batteries will also be affected. The irreversible ability and cycle efficiency have advantages. ， &’; For a lithium ion battery, the R group in the nitrite additive having the formula (RO) N (= 0) must contain 1 to 1 0

Page 19 α 4 7 1 6 5 V. Description of the invention (17) &quot; — A saturated or unsaturated organic radical of one carbon atom. Without intending to be limited to any particular theory, butyl) activation, the 0-R bond is quite weak and is believed to be ^^ (for example, by the Ν in the third-functional group [-0-N (= 0)] = 〇 bond, there is a nitrite interruption between oxygen and R. The nitrite intermediate can then effectively cut the bond between it and the solute to compete with the reaction of lithium, and the electrolyte solvent on the surface of the cathode Or that is: lithium nitrite or the product of the reduction of nitrite to form a nitrite. The formation of the surface (00N- (〇Li) n (n = 1 or 2) is formed on the cathode surface The performance of the obtained salt is more ionic than lithium oxide. Modification of the battery will lack the organic nitrite additive on the cathode: and the academic composition of lithium oxide and the possible form of the cathode surface protective layer: phase; The advantages of battery discharge characteristics are changed. This phase _ ^ = accompanied by pairs = reasons for improvement. As if having -U = = = concentration limit of nitrosyl ester additives is preferably about 0.001 The electrical concentration is about 0.20 Molar? If the concentration of the additive is less than about 0.001 Mo, then the advantages of the nitrite additive The effect is not obvious. In addition, the concentration of the 2 additives is greater than about .. 2. Moore concentration, because of the formation of :: Anion J: thin film and lower electrolyte conductivity ·, the advantages of the additive :: broken higher The harmful effects of the internal battery resistance are eliminated. It is to be understood that different changes to the concept of the invention described herein will be apparent to those skilled in the art, as defined by the scope of the attached patent application, 0 deviation The spirit and scope of the present invention.

Claims (1)

447165 6. Application scope 1. An electrochemical battery, which includes: a) a negative electrode, which is inserted with a metal test; b) a positive electrode, an electrode active material which contains an alkali metal; c) a non-aqueous electrolyte activation Negative and positive electrodes; and d) a nitrite additive provided in the electrolyte. 2. For an electrochemical battery as claimed in item 1 of the patent application, wherein the nitrite additive has the formula: (R0) N (= 0), where the R group is saturated or unsaturated with 1 to 10 carbon atoms. Saturated hydrocarbons, or organic groups of heteroatoms. 3. The electrochemical cell according to item 1 of the application, wherein the nitrite additive is selected from the group consisting of methyl nitrite, ethyl arsenate, propyl nitrite, isopropyl nitrite, Butyl nitrite, isobutyl nitrite, tertiary-butyl nitrite, fluorenyl nitrite, and phenyl nitrite, and mixtures thereof. 4. The electrochemical cell according to item 1 of the patent application scope, wherein the nitrite additive is present in the electrolyte in a range of about 0.01 mol concentration to about 0.20 mol concentration. 5. As for the electrochemical battery in the first item of the patent application scope, it claims that the nitrite additive is the third-butyl nitrite, and the concentration existing in the electrolyte is as high as about 0.5 Molar concentration 6 . For example, an electrochemical cell in the scope of patent application: where the electrolyte includes a quaternary, non-aqueous carbonic acid solvent mixture? 7. The electrochemical cell according to item 1 of the application, wherein the electrolyte contains at least one linear carbonate, and is selected from the group consisting of: dimethyl carbonate: diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate Esters, propyl carbonate and ethyl carbonate Page 21 447165 VI. Scope of patent application C and its mixture / 8. The electrochemical cell according to item 7 of the patent application, wherein the electrolyte contains at least three linear carbonates. 9. The electrochemical cell according to item 1 of the scope of patent application: wherein the electrolyte contains at least one cyclic carbonate, and is selected from the group consisting of: ethylene carbonate, propylene carbonate, butene carbonate and vinylene carbonate And its mixture ... 10 · The electrochemical cell according to item 1 of the patent application scope, wherein the electrolyte contains ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate. 1 1 · The electrochemical battery according to item 10 of the scope of patent application, wherein the range of ethylene carbonate is about 10% to about 50% by volume. The range of dimethyl carbonate is about 5% to about 75%. The range of methyl ethyl carbonate is about 5% to about 50%; and the range of diethyl carbonate is about 3% to about 45%. 1 2. The electrochemical cell according to item 1 of the scope of patent application, wherein the electrolyte comprises a material selected from the group consisting of LiPF6, LiBF4, LiAsF6, LiSbF6, LiC104, LiAlCl4, LiGaCl4, LiN03, LiC (S02CF3) 3, .LiN ( S02CF3) 2, LiSCN: Li03SCF2CF3., LiCeF5S03, Li02CCF3, LiS03F, LiB (C6H5) 4 &amp; LiCF3S03W and alkali metal salts of mixtures thereof. 13. The electrochemical cell as claimed in claim 1, wherein the alkali metal is lithium. 14. The electrochemical cell according to item 1 of the scope of patent application, wherein the negative electrode contains a negative electrode activating material, and is selected from the group consisting of: coke, carbon black, graphite, acetylene black: carbon fiber and glassy carbon and mixtures thereof . 1 5. The electrochemical cell according to item 1 of the scope of patent application, wherein the negative electrode activating material is mixed with a fluororesin binder. . Page 22, 447165 6. Application scope of patent 16. The electrochemical battery according to item 1 of the scope of patent application, wherein the positive electrode contains a positive electrode active material, which is selected from the group consisting of: vanadium, titanium, chromium, copper, molybdenum, silver 1Iron, nickel, bell oxides for diamonds and shoes, bell chemicals, bell compounds, bell compounds, and mixtures thereof. 17 &apos; As in the electrochemical application of item 16 of the application, wherein the positive electrode active material is mixed with a fluororesin binder. _ 1 8. The electrochemical cell according to item 16 of the scope of patent application, wherein the positive electrode active substance is conductive with far from acetylene black, carbon black, graphite, nickel powder, aluminum powder, titanium powder and stainless steel powder and mixtures thereof. Additives are mixed. 1 9. An electrochemical battery comprising: a) a negative electrode, which is inserted into a chain; b) a jt electrode, which includes an electrode active material and which is inserted with lithium; and c) an electrolyte solution to activate the negative electrode and The positive electrode, the electrolyte includes an alkali metal salt dissolved in a quaternary, rhenium aqueous carbonate solvent mixture, the solvent mixture being acid-broken vinyl ester, dimethyl carbonate, ethyl methyl carbonate, and carbonic acid-ethyl acetate; and d) Nitrite additive provided in the electrolyte. 2 0. The electrochemical cell according to item 19 of the scope of the patent application, wherein the nitrite additive has the formula: (R0) N (= 0), where the R group is saturated or not containing 1 to 10 carbon atoms. Saturated hydrocarbon, or organic group of heteroatom group. 2 1. The electrochemical cell according to item 19 of the scope of patent application, wherein the nitrite additive is selected from the group consisting of methyl nitrite, ethyl nitrite, propyl nitrite, and isopropyl isocyanate. Nitrate, butyl nitrite, isobutyl sulfite, tert-butyl nitrite, benzyl nitrite, and benzyl nitrite Page 23 447165 6. Scope of Patent Application Esters and their mixtures. 2 2. The electrochemical cell according to item 19 of the scope of patent application, wherein, by volume, the range of ethylene carbonate is about 10% to about 50%, and the range of dimethyl carbonate is about 5 % To about 75%. The range of methyl ethyl carbonate is about 5% to about 50; and the range of diethyl carbonate is about 3% to about 45%. 23. The electrochemical cell according to item 19 of the application, wherein the electrolyte comprises a material selected from the group consisting of LiPF6-LiBF4, LiAsF6, LiSbF6, LiCl04, LiAlCl4, LiGaCi4., LiN03, .LiC (S02CF3) 3, .LiN (S02CF3) 2. LiSCN: Li03SCF2CF3, LiC6F5S03, Li02CCF3., LiS03F, LiB (C6H5) 4, and alkali metal salts of LiCF3S03 and mixtures thereof. 24. —An electrochemical battery 'It contains: a) — a carbonaceous material negative electrode that can be inserted into the chain; b) — a positive electrode that contains an oxidation membrane; and c) a non-aqueous electrolyte activated negative electrode and positive electrode! The non-aqueous electrolyte contains a nitrite additive that contacts the electrolyte to provide lithium nitrite or a lithium salt of a nitrite reduction product on the surface of a lithium-inserted cathode. 2 5 · A method for providing an electrochemical cell, comprising the steps of: a) providing a negative electrode with an alkali metal inserted therein; b) providing a positive electrode with an electrode active material including an alkali metal inserted; c) using a non-aqueous material The electrolyte activates the negative and positive electrodes; and d) providing a nitrite additive in the electrolyte. 2 6. The method according to item 25 of the scope of patent application, comprising providing a nitrite additive having the formula: (R0) N (= 〇) where r is a carbon source containing 1 to 0 Page 24 447165: Patented saturated or unsaturated hydrocarbons, or organic groups of heteroatom groups. 2 7. The method according to item 25 of the patent application scope, which includes self-containing methyl nitrite, ethyl nitrite / propyl nitrite, isopropyl nitrite, and butyl nitrite. Among the groups of esters, isobutyl nitrites, tertiary-butyl nitrites, fluorenyl nitrites, phenyl nitrites, and mixtures thereof, the sulfite additive is selected. 2 8. The method according to item 25 of the patent application range, wherein the sub-squat acid ester additive is present in the electrolyte in a range of about 0.01 mol concentration to about 0.2 mol concentration. 2 9. The method according to item 25 of the scope of patent application, wherein the nitrite additive is a third-butyl nitrite, and the concentration existing in the electrolyte is as high as about 0.05 Molar concentration. . 30. The method according to item 25 of the patent application, comprising providing an electrolyte containing a quaternary, non-aqueous carbonate solvent mixture. 9 31. The method according to item 25 of the patent application, wherein the electrolyte contains at least one linear chain. The carbonate is selected from the group consisting of: dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl ethyl carbonate, methylpropyl carbonate, and ethylpropyl carbonate, and mixtures thereof. 3 2. The method of claim 31, wherein the electrolyte contains at least three linear carbonates. 33. The method according to claim 25, wherein the electrolyte contains at least one cyclic carbonate, and is selected from the group consisting of: _ ethylene carbonate. Propylene carbonate, butene carbonate, and vinylene carbonate. And its mixture ... 3 4. The method of claim 25, wherein the electrolyte contains Page 25 Λ 4716 5 VI. Scope of patent application Vinyl carbonate, dimethyl carbonate, ethyl ethyl carbonate and diethyl carbonate. 35. The method according to item 34 of the patent application range, wherein the volume range of vinyl carbonate is about 10% to about 50%, and the range of dimethyl carbonate is about 5% to about 75%. The range of ethyl methyl carbonate is about 5% to about 50%; and the range of diethyl carbonate is about 3% to about 45%. 36. The method of claim 25, wherein the electrolyte comprises a material selected from the group consisting of LiPF6: LiBF4, Li AsF6, LiSbF6, LiC104, UA1C14, LiGaCl4, .LiN03, LiC (S02CF3) 3-, LiN (S02CF3) 2. LiSCN, Li03SCF2CF3, LiC6F5S03, Li02CCF3, LiS03F, LiB (CsH5) 4, and alkali metal salts of LiCF3S03 and mixtures thereof. 37. A method as claimed in item 25 of the scope of patent application: comprising providing an alkali metal such as lithium. 38. The method of claim 25, including providing a positive electrode including a positive electrode activating material selected from the group consisting of: vanadium, zinc, chromium, copper, molybdenum, niobium, iron, and nickel. , Cobalt and manganese lithiated oxides, lithiated sulfides, bellitized selenides, and lithiated tellurides and mixtures thereof. 39. The method according to item 25 of the patent application scope, comprising providing a negative electrode including a negative electrode activating material selected from the group consisting of coke, carbon black \ graphite, acetylene black, carbon fiber, and glassy carbon and its mixture. Page 26