RU228030U1 - CYLINDRICAL LITHIUM-ION BATTERY WITH ANODE BASED ON LITHIUM TITANIUM OXIDE (Li4Ti5O12) - Google Patents

Abstract

The utility model relates to electrochemical energy, in particular, to lithium-ion batteries (LIB). An increase in the output currents, the ability to charge a lithium-ion battery at low operating temperatures down to minus 30°C, and an increase in the number of charge-discharge cycles are technical results that are achieved by the fact that the rolled-configuration electrode block contains a porous separator with a PVDF coating 16 μm thick, moistened with an organic electrolyte based on LiPF ₆ salt and solvents from ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, vinylene carbonate, while an aluminum foil 12 μm thick is coated on both sides with an active mass of the composition LiNiMnCoO ₂ , polyvinylidene fluoride, carbon nanotubes and carbon with the following ratio of the components of the active masses: LiNiMnCoO ₂ - 87-89%, polyvinylidene fluoride - 0.9-1.1%, carbon nanotubes - 10-12%, carbon - the rest, while the negative electrode is an aluminum foil with a thickness of 20 µm with an active mass applied to it on both sides made of lithium titanate Li ₄ Ti ₅ O ₁₂ - 93-95%, polyvinylidene fluoride - 1.5-2%, conductive carbon - 1-1.5% and multi-walled carbon nanotubes - the rest. 1 fig.

Description

The utility model relates to electrochemical energy, in particular, to lithium-ion batteries (LIB).

Known are cylindrical LIBs (patent IM RU No. 143063, published 10.07.2014, IPC H01M 10/0525, H01M 4/133), with a cathode based on lithium cobaltate, comprising a cylindrical housing with sealed positive and negative current terminals located on housing covers welded to opposite ends of the housing, a cylindrical block of negative and positive electrodes with active masses separated by a separator impregnated with electrolyte, current collectors of the electrodes welded to the corresponding current terminals, safety valves, characterized in that the electrode block is wound on a polypropylene pipe, the negative electrode is a copper foil with an anode active mass applied to it, consisting of graphite, polyvinylidene fluoride and carbon, with the following ratio of components, wt. %:

graphite - 90.0-96.0

polyvinylidene fluoride - 0.8-2.9

carbon is the rest, the positive electrode is an aluminum foil with a cathode active mass applied to it, consisting of lithium cobaltate, polyvinylidene fluoride and carbon, in the following ratio of components, wt. %:

lithium cobaltate - 90.0-95.0

polyvinylidene fluoride - 0.94-3.0

carbon - the rest

The disadvantages of this technical solution are that lithium cobaltate is used as the main material of the positive electrode, which has low load characteristics, high cost, low temperature stability, and increased fire and explosion hazard. And graphite is used as the main material of the negative electrode, which has its disadvantages in terms of low cycling resource, an increase in the volume of the graphite electrode during the development of cycles, irreversible capacity during the first charge cycle, and the impossibility of charging at negative temperatures.

A cylindrical lithium-ion battery with a cathode based on lithium-nickel-manganese-cobalt oxide (LiNiMnCoO ₂ ) is known (Patent FPM No. 213335, published 06.09.2022, H01M 10/0525, H01M 4/48, adopted as a prototype)

A cylindrical lithium-ion battery with a cathode based on LiNiMnCoO ₂ contains a corrosion-resistant drawn metal case, inside which there is an electrode block made of a roll design, consisting of a positive electrode and a negative electrode separated from each other by a porous separator with a ceramic coating 16 μm thick, the separator is moistened with an organic electrolyte based on LiPF ₆ salt and solvents of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, vinylene carbonate, the positive current terminal is spot welded to the cover, the negative current terminal is spot welded to the battery case, the cover is sealed and fastened to the case by beading, preliminary and final rolling, a heat-shrinkable tube is seated on the case by thermal action, the positive electrode is an aluminum foil 12 μm thick with an active mass applied to it, consisting of lithium nickel manganese cobalt oxide (LiNiMnCoO ₂ ), polyvinylidene fluoride, carbon nanotubes and carbon with the following ratio of active mass components: LiNiMnCoO ₂ 87-89%, polyvinylidene fluoride 0.9-1.1%, carbon nanotubes 10-12%, carbon is the rest, the negative electrode is a copper foil 8 μm thick with an active mass applied to it, consisting of 95-97% graphite, 1.3-1.6% sodium carboxymethyl cellulose, 3.7-4.5% anionic polymer dispersion, carbon is the rest, a charge-discharge controller is located at the minus contact location, connected to the plus and minus contacts of the battery with a nickel tape. Adopted as a prototype.

The disadvantage of the prototype is that the discharge currents are not high enough, since graphite is used as an anode material, as well as a low cycling resource and the impossibility of charging at low negative temperatures.

One of the problems of operation of cylindrical lithium-ion batteries with graphite anode is a low number of charge-discharge cycles, insufficiently high discharge currents, and the impossibility of charging the battery at temperatures below 0°C to maintain high fire and explosion safety characteristics. Since when the temperature drops below 0°C, lithium intercalation into the structure of the graphite electrode decreases sharply, lithium ions settle on the surface of the electrodes, due to which the irreversible capacity of the electrodes increases and the explosion and fire hazard increases.

The proposed utility model is a solution to this pressing problem of cylindrical lithium-ion batteries.

The technical result of the utility model is an increase in output currents, the ability to charge a lithium-ion battery at low operating temperatures down to minus 30°C, and an increase in the number of charge-discharge cycles.

The specified technical result is achieved by the proposed design of a cylindrical LIB.

A cylindrical lithium-ion battery with an anode based on lithium titanate oxide (Li ₄ Ti ₅ O ₁₂ ) contains a corrosion-resistant drawn metal case, inside which there is an electrode block made according to the type of a roll design, consisting of a positive electrode and a negative electrode separated from each other by a porous separator with a PVDF coating 16 μm thick, the separator is moistened with an organic electrolyte based on LiPF ₆ salt and solvents of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, vinylene carbonate, the positive aluminum current terminal is spot welded to the cover, two negative nickel current terminals located in the middle and one of the edges of the negative electrode are spot welded to the battery case, sealing and fastening of the cover to the case are made by beading, preliminary and final rolling, on the case by the method of thermal action the heat shrink tube is seated, the positive electrode is an aluminum foil 12 μm thick with an active mass applied to it on both sides, consisting of lithium nickel manganese cobalt oxide (LiNiMnCoO ₂ ), polyvinylidene fluoride, carbon nanotubes and carbon in the following ratio of active mass components: LiNiMnCoO ₂ 87-89%, polyvinylidene fluoride 0.9-1.1%, carbon nanotubes 10-12%, carbon is the rest, the negative electrode is an aluminum foil 20 μm thick with an active mass applied to it on both sides, consisting of lithium titanate oxide (Li ₄ Ti ₅ O ₁₂ ) 93-95%, polyvinylidene fluoride 1.5-2%, conductive carbons-1-1.5%, multi-walled carbon nanotubes are the rest. The number of charge-discharge cycles, increase in output currents, and the ability to charge at a reduced operating temperature of down to minus 30°C become possible due to the use of lithium titanate oxide (Li ₄ Ti ₅ O ₁₂ ) as the main material of the negative electrode. The advantage of a negative electrode based on Li ₄ Ti ₅ O ₁₂ , over conventional lithium-ion batteries with a graphite anode, is the absence of SEI film formation, as well as the absence of lithium deposition on the electrode surface during fast charging and discharging at low temperatures. Li ₄ Ti ₅ O ₁₂ is an ideal anode material due to its long-term cyclic stability due to zero deformation or a small change in volume during the introduction and extraction of lithium.

The thermal stability of Li4Ti5O12 at high temperatures is superior to other lithium-ion systems. In addition, Li4Ti5O12 prevents alloying of aluminum foil, which in turn allows the aluminum current collector to generate significantly higher capacity compared to the copper current collector.

The essence of the utility model is explained by a drawing.

Fig. 1 shows a sketch of the design of a cylindrical lithium-ion battery with an anode based on lithium titanate oxide Li4Ti5O12 with the necessary local sections.

The figure shows:

1 - corrosion-resistant drawn metal body;

2 - a block of electrodes manufactured using a roll design;

3 - negative electrode;

4 - positive electrode;

5- separator with ceramic coating;

6 - lid

7 - heat shrink tube;

8 - aluminum positive current terminal; 9 - nickel negative current terminals.

The cylindrical lithium-ion battery consists of a corrosion-resistant drawn metal case 1, inside which there is an electrode block made according to the type of roll design 2, consisting of negative 3 and positive 4 electrodes separated from each other by a porous separator 5 with a PVDF coating 16 μm thick, and moistened with an organic electrolyte based on LiPF salt ₆ and solvents of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, vinylene carbonate, the positive aluminum current terminal 8 is welded by contact spot welding to the cover 6, the negative nickel current terminals of the negative electrode are welded by contact spot welding to the case 1, the sealing and fastening of the case 1 to the cover 6 are carried out by the method of beading, preliminary and final rolling, a heat-shrinkable tube 7 is seated on the case by the method of thermal action, the positive electrode 4 is an aluminum foil with a thickness 12 μm thick with an active mass applied to it on both sides, consisting of lithium nickel manganese cobalt oxide (LiNiMnCoO ₂ ), polyvinylidene fluoride, carbon nanotubes and carbon in the following ratio of active mass components: LiNiMnCoO2 87-89%, polyvinylidene fluoride 0.9-1.1%, carbon nanotubes 10-12%, carbon the rest, the negative electrode 3 is an aluminum foil 20 μm thick with an active mass applied to it on both sides, consisting of lithium titanate oxide 93-95%, polyvinylidene fluoride 1.5-2%, conductive carbons-1-1.5%, multi-walled carbon nanotubes the rest.

The cylindrical lithium-ion battery operates as follows. When charging, the positive terminal of the charger (not shown in the figure) is connected to the battery cover, the negative terminal to the opposite side, which ensures the flow of current through the positive 4 and negative 3 electrodes, providing the processes of oxidation-reduction reaction on the negative electrode 3 and deintercalation of lithium from lithium nickel manganese cobalt oxide (LiNiMnCoO2) on the positive electrode 4. When discharging, the process occurs in the reverse order.

The charge/discharge process can be described by the oxidation-reduction reaction formula:

Reaction at the anode: Li ₄ Ti ₅ O ₁₂ +3Li+3e⇔2Li ₇ Ti ₅ O ₁₂

Separator 5 prevents short circuit of electrodes during battery assembly and ensures uniform access of electrolyte to electrodes. Thus, a set of essential features of the utility model is provided: increase of output currents, possibility of charging lithium-ion battery at low operating temperatures down to minus 30°C, increase of number of charge-discharge cycles.

An example of the implementation of a utility model.

20 samples of batteries with a capacity of at least 1.0 Ah, manufactured according to the proposed version, were manufactured and tested.

Discharged batteries in the amount of 20 pcs. were connected to a charging and discharging stand, a voltmeter and discharged with currents from 0.5 A to 20.0 A under normal climatic conditions. In this case, all tested samples were discharged without reducing the voltage below the final permissible value and gave the required capacity.

Tests were also conducted to charge batteries at a reduced operating temperature of minus 30°C, and the capacity of all tested samples was at least 50% of the capacity given under normal climatic conditions.

Based on the above, it can be concluded that the proposed utility model can be implemented in practice with the achievement of the stated technical result.

Claims (1)

A cylindrical lithium-ion battery with an anode based on lithium titanate oxide (Li ₄ Ti ₅ O ₁₂ ) containing a corrosion-resistant drawn metal case, inside which there is an electrode block made according to the type of a roll design, consisting of a positive electrode and a negative electrode separated from each other by a porous separator 16 μm thick, the separator is moistened with an organic electrolyte based on LiPF ₆ salt and solvents of ethylene carbonate, ethyl methyl carbonate, dimethyl carbonate, vinylene carbonate, sealing and fastening of the cover to the case are carried out by the method of beading, preliminary and final rolling, a heat-shrinkable tube is seated on the case using the method of thermal action, the positive electrode is an aluminum foil 12 μm thick with an active mass applied to it, consisting of lithium nickel manganese cobalt oxide (LiNiMnCoO ₂ ), polyvinylidene fluoride, carbon nanotubes and carbon with the following ratio of active mass components: LiNiMnCoO ₂ - 87-89%, polyvinylidene fluoride - 0.9-1.1%, carbon nanotubes - 10-12%, carbon - the rest, characterized in that the negative electrode is an aluminum foil 20 μm thick with an active mass applied to it on both sides, consisting of lithium titanate oxide (Li ₄ Ti ₅ O ₁₂ ) - 93-95%, polyvinylidene fluoride - 1.5-2%, conductive carbons - 1-1.5%, multi-walled carbon nanotubes - the rest, a separator 16 μm thick with a PVDF coating.