Supercapacitor and method of its construction

Abstract

A supercapacitor consisting of a tight protective housing, first and second electrodes, which are electrically insulated from each other. One or both electrodes are also insulated from the housing. Free volume of the cell and the space between the electrodes are filled with electrolyte fluid. On the surface of the first electrode there are applied carbonaceous materials comprising C-14 isotope. Method of supercapacitor construction lies in the preparation of the first and second electrodes with application of the surface layer made of carbonaceous materials, allocation of the first and second electrodes inside the tight housing and their electric insulation from each other, filling of the housing with electrolyte fluid. Into the layer of carbonaceous materials onto the surface of the first electrode the C-14 isotope is introduced.

Claims

1. A supercapacitor comprising: a sealed protective housing; a first electrode, being an operating electrode, and a second electrode, being an auxiliary electrode, the first and second electrodes placed inside the housing and in electrical isolation from each other, and one or both of the electrodes also being electrically isolated from the housing, and electrolyte, the electrolyte filling the housing and space between the first and second electrodes; wherein the first electrode comprises a surface layer of carbonaceous materials on an inner portion of the first electrode, wherein the layer of the carbonaceous materials at the surface of the first electrode is in the form of an any of carbon nanotubes (CNTs), fullerenes, graphene, soot, graphite or any mixture thereof, the layer of carbonaceous materials containing C-12 natural isotope, and the layer of carbonaceous materials being impregnated with a chemical compound comprising the C-14 isotope.

2. The supercapacitor according to claim 1, comprising a separator placed between the electrodes, wherein the separator is configured to prevent mechanical contact of the opposite electrodes and mixing of cathodic and anodic electrolytes.

3. The supercapacitor according to claim 1, wherein the electrodes are made of silicon, molybdenum, niobium, tungsten, or zirconium; or an alloy based on silicon, molybdenum, niobium, tungsten, or zirconium; or a corrosion-resistant steel.

4. The supercapacitor according to claim 1, wherein at least one of the radionuclides selected from the group consisting of H-3, nickel-63, Sr-90, Kg-85, At-241, Ac-227, and Th-229 are placed on the surface or inside of the carbon nanotubes.

5. The supercapacitor according to claim 1, wherein an acid solution, an alkali solution, or a solution of a salt is used to provide the electrolyte.

6. A method of supercapacitor construction, comprising: preparing a first electrode and a second electrode with application of a surface layer of carbonaceous materials on an inner portion of the first electrode; placing of the first and second electrodes in a sealed housing and in electrical isolation from each other; and filling the housing with an electrolyte; wherein C-14 isotope is introduced into the layer of the carbonaceous materials; and wherein the layer of carbonaceous materials at the surface of the first electrode is formed as an array of carbon nanotubes (CNTs), fullerenes, graphene, soot, graphite or any mixture thereof, the layer of carbonaceous materials containing C-12 natural isotope, and the layer of carbonaceous materials being impregnated with a chemical compound comprising the C-14 isotope.

7. The method of supercapacitor construction according to claim 6, wherein an alcoholic solution of aniline hydrochloride with the C-14 isotope is used in the capacity of a compound for impregnation of the array of carbonaceous materials at the surface of the first electrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic illustration depicting an example of the structure of a self-charging supercapacitor.

(2) FIG. 2a is a schematic illustration depicting the structure of a studied cell.

(3) FIG. 2b depicts an exterior of the studied cell of FIG. 2a.

(4) FIG. 3 is a graph depicting dynamics of charging of an illustrative cell with aniline hydrochloride with the C-14 activity equal to 1.74 and 6.0 mCi.

(5) FIG. 4 is a graph depicting dynamics of discharging of the cell with aniline hydrochloride with the C-14 activity equal to 1.74 mCi.

(6) FIG. 5a is a graph depicting dynamics of charging of a cell with an array of CNT on a substrate impregnated with aniline hydrochloride with the C-14 activity equal to 1.74 mCi in a cell filled with distilled water.

(7) FIG. 5b is a graph depicting dynamics of discharging of a cell with an array of CNT on a substrate impregnated with aniline hydrochloride with the C-14 activity equal to 1.74 mCi in a cell filled with distilled water.

(8) FIGS. 6a and 6b are graphs depicting dynamics of charging of a cell with aniline hydrochloride with the C-14 activity equal to 6 mCi with the electrolyte 0,1 n H.sub.2SO.sub.4 (FIG. 6a) and changing of the discharge current in the stationary mode at the load of 10 kOhm (FIG. 6b).

(9) FIG. 7 is a graph depicting changing of the voltage and current at the load in the “charge-discharge” mode at the cell with aniline hydrochloride with the C-14 activity equal to 6 mCi with the electrolyte 0.1 n H.sub.2SO.sub.4.

(10) FIGS. 8a and 8b are graphs depicting dynamics of charging of a cell with aniline hydrochloride with the C-14 activity equal to 6 mCi with the electrolyte 0,01 n NaOH (FIG. 8a) and changing of the discharge current in the stationary mode at the load of 10 kOhm (FIG. 8b).

DETAILED DESCRIPTION

(11) In FIG. 1, a structure of a self-charging supercapacitor is presented. It consists of a metal substrate (i.1), on which an array of carbon nanotubes (CNTs) has been grown, which incorporate the C-14 radioactive isotope (i.2). The substrate is placed into a fluoroplastic housing (i.3), where it stays in contact with the lower electrode (i.4) with the external led (i.5). The separator (i.6), which prevents mechanical contact of the opposite electrodes and obstacles mixing of the cathodic and the anodic electrolytes, is placed above the active substrate. The cell housing is filled with the electrolyte (i.7) and closed with the plastic cover (i.8). The second electrode (i.9) is inserted into the cover. The cover (i.8) seals the cell.

(12) In FIG. 2(a, b), the structure and the exterior of the mock-ups of the studied supercapacitor cells are presented. The cell consists of housing 1 and cover 2 made of stainless steel, inside of which fluoroplastic housing 3 and electrode-collector 4 isolated from the cover with fluoroplastic washer 5 are located. The operating electrode under study 8 in the form of a substrate is placed with the coating facing up on rubber ring 6 and pressed to it with fluoroplastic insert 7. The electric wire with a terminal is lead from the substrate's lower side using a spring contact with a screw. The cell is filled with an electrolyte through hole 4 in the electrode.

(13) Under the given dimensions, the visible part of the substrate makes 0.5 cm.sup.2, and the dry cell's electrical capacity makes 82 pF.

(14) Preparation of the substrates with CNT was performed by means of multiple serial applying of the alcoholic solution of aniline hydrochloride, which contains C-14 isotope, on the nanotubes. The applied isotope's activity was determined by means of the estimations based on the measurements of the substrate weight before and after impregnation with the reagent using the specific activity characteristics measured by the calorimetric method. The activity of the carbon-14 isotope determined by this method was equal to 1.74 and 6 mCi for two different similar type substrates. Additionally β-flow from the substrate equal to 0.8×10.sup.5 and 2.25×10.sup.5 min.sup.−1 cm.sup.−2 was measured.

(15) The study of the electrical performance of the supercapacitor cells has been conducted using the digital Nano voltmeter III-31 (measurements at the dry and filled with electrolyte cells) and a specially prepared automated measuring system based on the analog-digital modules ADAM 4017+, which facilitates the long-term measurements in the automatic mode (the cells filled with electrolyte).

(16) Embodiment of the invention is illustrated by the following examples.

Example 1

(17) The substrates with the preliminarily formed one-side coatings in the form of a CNT array of ˜10 μm thick were impregnated with the solution of aniline hydrochloride, wherein about a half of the carbon atoms were those of the C-14 isotope. The total activity of the C-14 as determined by the increase of the substrates' masses after drying was equal to 1.74 and 6.0 mCi for the first and the second substrates, respectively. The substrates were placed into the cells with the described above structure; the cell voltage was registered as a charge due to the C-14 isotope beta-decay. The kinetics of charging of the dry cells is presented in FIG. 3.

(18) Charging of the cells proceeds with the negatively charged electrons emission, in result of which the substrate with the CNT acquires a positive charge. After charging the cells during a full day and reaching the voltage of about 400 mV, the cells were discharged at the load resistor while registering the voltage at it. The cell discharge at the 10 kOhm resistor continued for several fractions of a second, and at the resistor of 47 MOhm—for several minutes. The charge dynamics in the latter case is presented by the diagram in FIG. 4.

(19) At the initial period of the cell discharge, which lasts for 10 minutes, the discharge curve has an exponential character. Then, a serious deviation from the exponent follows, and in the stationary mode, the discharge curve stabilizes at a constant level, which is determined by equality of the speeds of cell discharging and charging, and the letter one is determined by activity of the beta-source on the substrate.

(20) The described experiments demonstrate a low efficiency of the dry cell under direct charging by the beta-decay electrons, since only a part of the electrons participates in the cell charging process reaching the electrode-collector. Additionally, a part of the beta-decay electrons compensates the substrate's positive charge being absorbed in the CNT array on the substrate.

Example 2

(21) The cell with a substrate of the C-14 activity equal to 1.74 mCi after the experiments with the dry cell charging and discharging was filled with distilled water. The characteristics of the cell charging and discharging were measured.

(22) Dynamics of change of the voltage at the cell and the discharge current at the load resistor 10 kOhm are presented in FIG. 5.

(23) In the initial time moment during ˜20 hours starting from filling with water, the cell efficiency is low because of a low ion conductivity of clean water. The cell voltage at this stage mostly did not exceed 50 mV. After dissolution of a part of aniline hydrochloride from the substrate in the water with production of the additional ions in it, the voltage at the cell gradually increases during the following 10-12 hours. In the stationary mode, the voltage at the cell stabilizes verging towards the constant value of ˜300 mV and maintains at this level unless there is a water in the cell. At this stage, the current of cell loading at the resistor equal to 10 kOhm (FIG. 5b) stabilizes making about 1 mcA/cm.sup.2.

(24) The described experiment proves that the efficiency of a cell filled with distilled water as well as of the transformer and accumulator of the electric energy with an array of CNT with the carbon-14 is substantially higher than that of a similar cell with no water.

Example 2

(25) The cell with the substrate prepared as described in Example 1 with an array of CNTs impregnated with aniline hydrochloride with the C-14 activity equal to 6 mCi was dried after performing the experiments with charging and discharging in the cell with distilled water and, then, filled with the electrolyte 0.1 n H.sub.2SO.sub.4.

(26) The change of voltage at the cell is characterized by the time diagram presented in FIG. 6a, and the discharge current dynamics in the stationary mode at the load 10 kOhm is presented in FIG. 6b.

(27) In the initial moment, the discharge current in the peak mode reaches 4 mcA/cm.sup.2, and after that drops to 1 μA/cm.sup.2, and in the intermediate period reaches the maximal value of 1.5 μA/cm.sup.2. Additionally, the finish section of the discharge curve is presented in the diagram, when the current drops to zero that is related to evaporation (or radiolysis) of the water from the untight cell.

(28) In FIG. 7, the diagram of the cell operation in the “charge-discharge” mode, when using the load resistor of 10 kOhm, is presented.

(29) The diagram shows that in the moment of the load resistor 10 kOhm connection to the cell, the discharge current (curve 2) reaches the maximal value of 4-9 μA/cm.sup.2, and then, during several seconds, drops to 2 μA/cm.sup.2. When disconnecting the load resistor, the voltage at the cell (curve 1) ramps due to internal charging, in two seconds reaches 50-70 mV, and reaches 90-100 mV at the end of 5-second cycle.

Example 3

(30) The cell with the substrate with the CNT array impregnated with aniline hydrochloride with the C-14 activity equal to 6 mCi after performing the experiments with charging and discharging in the cell with 0.1 n H.sub.2SO.sub.4 as described in the previous Example 2 was dried and then filled with the electrolyte 0.01 n NaOH.

(31) The change of the voltage at the cell is characterized by the time diagram presented in FIG. 8a, and the discharge current dynamics in the stationary mode at the load 10 kOhm is presented in FIG. 8b

(32) In the cell with the electrolyte 0.01 n NaOH, similarly to that in the cell with the electrolyte 0.1 n H.sub.2SO.sub.4, self-charging of the supercapacitor double layer due to the beta-decay energy up to reaching the stationary level of ˜300 mV takes place. In the initial time period, the discharge current at the load 10 kOhm increases up to 18 μA/cm.sup.2, and then decreases smoothly reaching the stationary value of ˜40 μA/cm.sup.2.

(33) Thus, in the experiments with the use of the electrolytic cells with the electrodes in the form of the substrates containing the CNT arrays with the C-14 radioisotope, operation of the self-charging supercapacitor has been demonstrated. The device provides multiple charging and discharging without any external current supply.

(34) The above stated data proves that when using the claimed invention the following set of conditions is ensured:

(35) the device in the form of a supercapacitor, embodying the claimed invention when being embodied, provides accumulation and storage of electrical energy without charging from the external sources;

(36) the claimed invention for supercapacitor charging uses beta-decay of the C-14 isotope, the half-life of which makes 5700 years. When the device tightness is ensured, the consumption of the materials of the cell's electrode and housing made of the corrosion-proof alloys is minimal, the electrolyte consumption is zero.
for the claimed device and the method of its construction as described by the independent claims of the presented claims, feasibility of its embodiment using the described in the claim or known before the priority date facilities and methods has been proven.
the device, embodying the claimed invention, is able to ensure the achievement of the technical result anticipated by the applicant.

(37) The invention advantage is as follows:

(38) Increasing of transformation efficiency of the beta-decay energy into the electric energy, that becomes apparent in the increase of the generated current and power as compared with the analogs.

(39) Reducing of production costs of power supply made in the form of a supercapacitor due to application of the C-14 isotope—one of the cheapest (per activity unit) and available at the market isotopes, and due to simplification of the structure and technology of the device production.

(40) The proposed device can be produced using the already available experience in production of the mobile device power supplies, which use the supercapacitors with the electrodes, wherein the electrode coatings with the arrays of carbon nanotubes are applied.

(41) Hence, the claimed invention complies with the requirement to “industrial applicability”.

(42) Features of Technical Result Achievement

(43) Feature No. 1 is that in the device, which converts the energy of the radioactive beta-decay into the electrical energy, a supercapacitor is used, operating electrode(s) of which is made in the form of a substrate with a carbon nanotubes array.

(44) Feature No. 2 is that the substrate with an array of carbon nanotubes is impregnated with a chemical compound solution, which includes the C-14 isotope, or the carbon nanotubes are made using the C-14 isotope.

(45) Feature No. 3 is that the substrate with the array of carbon nanotubes is placed into an electrolyte, wherein the double layer formed at the boundary between each nanotube in the array and the electrolyte, being an asymmetrical potential barrier for the generated while decay charges, plays the role of the charges efficient separator and simultaneously the electric energy accumulator.