JP2013165051A - Battery cathode material and air secondary battery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon-based cathode material that can overcome functional deterioration of a positive electrode caused by repetitive charge/discharge in an air secondary battery.SOLUTION: Functional deterioration and gas generation in a long charge-discharge cycle are overcome by forming a positive electrode of an air secondary battery with "sawdust white charcoal" manufactured using, as materials, timber, timber fragments, timber sawdust, as well as sawdust, fragments and small chips of palm shells or the like. These materials are processed into a solid shape and carbonized at temperatures of 700-1350°C.

Description

  The present invention relates to a positive electrode material for a battery and an air secondary battery.

  Currently, air battery primary batteries are a small area, but have been developed as practical batteries and sold on a commercial basis, but air secondary batteries have not yet been put into practical development. A carbon material mainly used as a positive electrode of an air primary battery is a carbonized material obtained by adding a precious metal catalyst such as Pt (platinum) to porous activated carbon having electrical conductivity.

Carbonized materials used in practical applications or teaching materials as positive electrodes for air batteries include the above-mentioned activated carbon and Bincho charcoal (electrically conductive) that has been carbonized and fired at high temperatures, but their common features are extremely large. It has internal pore area (500-2000 m ² / g) and has electric conductivity as a battery positive electrode. However, carbonized material based on activated carbon, although the adsorption capacity, such as oxygen gas is excellent, OH to the electrolyte of the oxygen gas (O ₂₎ on its own ^- ion dissociation ability is small, high catalyst capability request In such a case, a noble metal catalyst such as Pt is added.

On the other hand, carbonized materials such as Bincho charcoal with high hardness carbonized at high temperature have a low ability to decompose OH ^- ion from oxygen gas as a battery positive electrode, and lack a positive electrode function as a practical battery, Used for science teaching materials such as air batteries.

  The above-mentioned two types of electrically conductive carbonized materials have a positive and negative function as an air battery, that is, a positive electrode as a primary battery only for discharge. An air secondary battery with a discharge function has not been developed yet.

  One of the factors hindering the use of air batteries as secondary batteries is known to be the functional deterioration of the carbon cathode material due to the large current during the charging process and the problem of gas generation from the electrolyte due to the charging current. It needs to be solved. Furthermore, it is also necessary that the weight recovery by charging the negative electrode metal (such as zinc metal) is excellent.

  To solve these problems, improvements and reforming of the cathode material, optimization of the catalyst metal to be added, optimization of the electrolyte, etc. are being promoted. They refuse to develop secondary batteries. Moreover, the absence of the air secondary battery limits the industrial application of the air battery having high energy density and excellent environmental compatibility to a very narrow range.

JP 2005-85719 A

  An object of the present invention is to develop a new carbon positive electrode material that overcomes the functional deterioration of the positive electrode that occurs due to repeated charge-discharge in an air battery, and to provide a stable air secondary battery thereby.

  The battery positive electrode of the present invention uses “oga white charcoal”, which has been previously defined, and is made from various kinds of wood, coconut shells, etc. “sawdust” and small pieces, which are processed into solids and carbonized at high temperatures. Configure. This carbonized material is also a rare carbonized material whose electric conductivity σ exhibits a “positive temperature coefficient” near room temperature. While most carbonized materials have metal electrical conductivity (negative temperature coefficient), the positive temperature coefficient of “oga shirako” is a very rare characteristic, and the temperature coefficient of semiconductor electrical conductivity σ (positive) Temperature coefficient). The origin of this unique electrical conductivity is related to the fact that “Oga Shira coal” is composed of ultrafine carbonized structure (graphene), and research on detailed electrical conduction mechanisms is still underway. Yes.

  The characteristic of “Oga-Shira coal” is that the function of the air battery positive electrode (oxygen electrode) can be achieved without adding a precious metal such as platinum (Pt) in bulk shape, powder shape, or ceramic processed plate shape from powder. Is to have. This is described in published patent publication 2005-85719.

The second characteristic of the carbonized material of the present invention is that the carbon structure of the positive electrode is stable not only in the discharging process of the battery but also in the charging process, and almost deteriorates the function as the positive electrode even after repeated charging and discharging. Absent. The stability and toughness of the secondary battery as a positive electrode are as follows. This is a carbonized material with ultrafine graphene grains, which is a feature of the carbonized material, and has a wide internal pore area (600 m ² − 1000 m ² / g). Furthermore, it is considered that one of the reasons for stability is that a catalyst such as platinum (Pt) is not added to the carbon structure.

Another important property of the “oga white coal” positive electrode is that it has a high ability to efficiently reabsorb (or adsorb) a large amount of OH ⁻ ions generated during the charging process, and suppresses the generation of oxygen gas generated during the charging process. That is. This function is a useful property as a secondary battery positive electrode that enhances battery output and performs stable charge-discharge.

  INDUSTRIAL APPLICABILITY The present invention makes it possible to develop a positive electrode material manufacturing technology for an air secondary battery that uses a carbon positive electrode material (oga white coal) that is stable against repeated charging and discharging, and the development of an air secondary battery thereby. .

  The present invention makes it possible to produce an air secondary battery that has not yet been practically developed, and enables industrial application of a large-capacity air secondary battery excellent in environmental performance and resource. Further, it becomes possible to develop a charge-discharge type composite battery system connected to a solar battery or the like.

Discharge output characteristics of an air primary battery composed of positive electrode made of sawdust. Charging-discharging output characteristics of an air secondary battery composed of a positive electrode made of white charcoal. The charge-discharge output voltage of 20 cycles of an air secondary battery, and the weight recovery rate of a negative electrode metal (zinc). Discharge characteristics of air secondary battery with respect to carbonization temperature of sawdust. Discharge characteristics of an air secondary battery using a positive electrode in which nitrogen atoms are added to sawdust. The structural example of the air secondary battery which mixed the hydrogen occlusion metal in the negative electrode, and mixed the white charcoal and NiOOH in the positive electrode. Charge-discharge characteristics of an air secondary battery in which a hydrogen storage alloy is used for the negative electrode, and white coal and NiOOH are mixed for the positive electrode. The structural example of the composite battery system connected with the air secondary battery module, a solar cell, wind power generation, etc.

Definition of word

“Oga white coal” which is a positive electrode material of the air secondary battery which is the base of the present invention is defined below and referred to in the description.
“Oga white charcoal” is a solid compression of sawdust and debris such as wood, palm, etc., and carbonized under high temperature conditions from 700 ° C to 1350 ° C. A carbon material that exhibits gas (O ₂ ) adsorption ability and dissociation ability (reduction ability) into OH ⁻ ions in the electrolyte.

  In various experimental approaches that demonstrate the present invention, a two-step process is taken. One is establishment of carbonization conditions for sawdust, which is a positive electrode material, as a first step in order to obtain a sufficient function as a positive electrode of a secondary battery and durability of the positive electrode by repeated charge-discharge. Here, starting from various sawdust, their solid processing and determination of the range of required carbonization temperatures.

  The ability of the positive electrode manufactured with various raw materials and carbonization conditions was judged from the charge-discharge characteristics of an air secondary battery that was configured as a positive electrode. In this test, the recovery rate of the battery output in the constant current discharge to the load and the weight recovery rate of the negative electrode metal (zinc) were intensively investigated in repeated charging and discharging. We also focused on carbon structure cracks and functional deterioration due to charge-discharge, which are important issues for the positive electrode.

<Carbonizing conditions for ogashira coal>
The important point in the carbonization conditions of “oga white coal” that forms the basis of the present invention is the solid processing of sawdust and the determination of the carbonization temperature thereof. The compressive strength to solid differs depending on the raw material of sawdust, and in this experiment, solid processing was performed in the range of 5 to 120 atmospheres. Although the pressure during solid processing varies depending on the type of sawdust, it has been found that the hardness required for high-temperature carbonization can be obtained at the above pressure.

  An important point in the production of white charcoal cathode material is the carbonization temperature of the solid processed sawdust. As a condition for developing the capacity of the secondary battery, from this experiment, it was possible to produce sawdust with excellent secondary battery positive electrode characteristics only in a high temperature range of 700 ° C to 1350 ° C.

  After establishing the carbonization conditions for sawdust, further investigate the effect of adding nitrogen (N) atoms or molecules to sawdust for further improvement of the positive electrode capacity, and add for significant improvement in capacity. The conditions were determined. The adsorption rate of N atoms on the carbon wall of white coal was evaluated by comparing the spectrum intensity of C atoms by XPS method and the spectrum intensity from N atoms bonded to carbon, and the addition rate (%) of N atoms. .

The second step is an experiment of the configuration and charge-discharge characteristics of the secondary battery for obtaining data on the function and durability of the positive electrode as the air secondary battery. Here, various types of negative electrode metals were investigated, but secondary battery experiments using zinc, which has a proven track record as negative electrodes for batteries, were mainly performed.
The other reason for mainly using zinc is that the recovery rate of the weight of zinc by charging showed an excellent characteristic of 99% or more. Of course, the negative electrode metal is not limited to zinc, and any metal that is stable and has a good weight recovery rate as a negative electrode of a secondary battery can be applied to the battery of the present invention.

<Basic configuration of secondary battery>
50 g of “oga white coal” filled as the positive electrode was used in the primary battery and the secondary battery. The battery charge-discharge test is performed at room temperature. In order to improve the discharge capacity in the primary / secondary battery configuration of the battery, the “Oga white coal” powder and the commercially available electrically conductive activated carbon powder are kneaded, and also in the positive electrode subjected to N treatment. The weight of the carbonized material for the positive electrode is all 50 g.

<Electrolyte>
The electrolyte was composed of an aqueous solution such as KOH, NH ₄ Cl, NaOH, ZnCl ₂ or a mixed solution thereof used in many batteries. Here, a description will be given using results of an electrolytic solution based on an NH ₄ Cl-aqueous solution (20%) that is inexpensive and easy to handle.

The contents of the present invention will be described below based on examples. Before the secondary battery experiment, the discharge characteristics of the basic air primary battery will be described. FIG. 1 shows the discharge characteristics of an air battery having bulk-shaped “oga white coal” as a positive electrode. The positive “oga white charcoal” was processed into a square plate shape, and a carbon electrode was attached to extract current. The positive electrode weight excluding the carbon electrode was 50 g. As the electrolytic solution, a 20% NH ₄ Cl aqueous solution was used.

  An air primary battery was composed of two types of battery, battery #A having a negative zinc (Zn) weight of 15 g and battery #B having 6 g, and the discharge characteristics were compared. The battery (#A) filled with 15 g of the negative electrode metal (zinc) reached a steady output at an electromotive force of about 0.8 V with a constant current discharge of 50 mA, and thereafter maintained a stable battery operation even after 150 hours of discharge. This discharge amount is 7500 mAh, and the zinc weight of the negative electrode is reduced by about 9 g, and zinc is still about 6 g.

  On the other hand, in the case of air battery #B filled with 6 g of zinc, the battery output voltage rapidly decreases in the same discharge in about 90 hours of discharge time. This decrease in power indicates that the charged zinc has begun to be depleted. When the depletion of the negative electrode metal begins, the output of the air primary battery decreases rapidly, losing battery capacity and ending the life of the primary battery. FIG. 1 is basic data for understanding the limit of the discharge capacity of the primary battery, and is data to be compared with the following discharge characteristics of the secondary battery.

<Explanation of Claims 1-4>
The air secondary battery using zinc as a negative electrode metal will be discussed based on the basic chemical reaction formula of the following discharge-charge process. We will not go into more detailed reaction processes here.
(Discharge): Zn ²⁺ + 2OH ⁻
→ Zn (OH) ₂ (intermediate product) → ZnO (solid) + H ₂ O
(Charge): Zn (OH) ₂ (intermediate product) → Zn ²⁺ + 2OH ⁻

Zn (OH) ₂ which is an intermediate product generated in the discharge process eventually changes to stable ZnO (solid), but charging from ZnO is difficult, and Zn (OH) which is an intermediate product The reverse reaction from OH) ₂ to Zn ²⁺ and 2OH ⁻ is utilized. ZN ²⁺ is reduced to Zn (metal solid) as the negative electrode, and OH ⁻ is absorbed by the positive electrode or released as oxygen gas. The OH ⁻ ions reabsorbed by the positive electrode can contribute to the discharge current together with the OH ⁻ ions generated from oxygen gas replenished from the outside.

  The electrode configuration of the air secondary battery was the two-electrode configuration of the primary battery and the three-electrode configuration with the second positive electrode made of another carbon rod. The reason for the three-electrode configuration is to confirm a remarkable difference in charge-discharge characteristics between the positive white carbon positive electrode and the carbon rod positive electrode.

In the experiment, as compared with the charging characteristics using a carbon rod as a positive electrode, the charging-discharging characteristics in a two-electrode configuration of zinc negative electrode-ogo charcoal / positive electrode were significantly improved. This result indicates that the “oga white charcoal” positive electrode is a stable positive electrode with little functional deterioration in both the discharging process and the charging process. Moreover, the battery output after charge was greatly improved. This is because high-concentration OH ⁻ ions generated during the charging process are efficiently absorbed by the positive electrode of the white coal, or the intercalation of OH ^{− into} the white coal occurs, improving the output of the air battery after charging. I found out.

  On the other hand, in the charging experiment using the added carbon positive electrode, gas generation during charging was significant, and the battery output after charging was not improved. Below, it demonstrates using the result of the two-electrode battery of the charcoal positive electrode-zinc negative electrode which showed the stable charge-discharge function.

  Up to 3 basic experiments were conducted on the charge-discharge characteristics as a secondary battery. The air battery used in this charge experiment was an air battery with a zinc filling of 10 g, and was charged 3 times after discharging at 50 mA for 90 hours. -The discharge characteristics were examined.

  FIG. 2 shows the result of charging the battery for 10 hours under a constant current condition of 300 mA and then discharging for 90 hours for 3 cycles. The charging voltage (300 mA) varied from the initial 1.3 V to the final value of about 2.0. All discharge experiments were performed at 50 mA (constant current discharge).

  The voltage of the battery after the first charge is remarkably increased from that before the charge. In the discharge for about 20 hours, a high output voltage of 1.0V-1.5V is generated. Furthermore, in long-term discharge, it stabilizes to about 1V. In all three charge-discharge experiments, discharge characteristics exceeding the battery output before the first charge are observed.

The recovery rate of the battery output after the three times of charging was 120% or more in comparison with that before the charging, and the weight recovery rate of zinc of the negative electrode showed a high recovery rate of 99% or more in all three times. . It is an unexpected effect that a high battery output is generated in a long period of 20 hours or more after charging from the battery output (50 mA, 0.8 V) before charging, and this is caused by activation of zinc metal by charging, and a high concentration of OH generated in charge ^- is working absorption effect due to the positive pole of the ions.

  FIG. 3 shows the results of 20 charge-discharge tests of an air secondary battery having a positive electrode made of white coal from wood sawdust. All the discharges were investigated for the output voltage of the battery and the recovery rate (%) of the weight of the negative electrode zinc at 50 mA constant current discharge. The 20 chargings were all 400 mA for 10 hours. The recovery rate of the output voltage of the battery was evaluated based on the discharge output after one charge because the output was improved to 130% or more after the first charge.

  It can be seen that the battery voltage at 50 mA discharge shows excellent recovery characteristics of 99% or more in 20 cycle tests. In addition, the weight recovery rate of the negative electrode zinc was 99% or more.

<Types and carbonization conditions of positive white carbon coal>
In order to investigate an appropriate carbonization temperature for further improving the function of the positive white charcoal cathode, positive electrodes were produced at various carbonization temperatures using wood sawdust and palm sawdust as raw materials. FIG. 4 shows the results of evaluating the battery output of an air secondary battery using sawdust charcoal carbonized at various temperatures as the positive electrode and the weight recovery rate of the zinc negative electrode by 20 charge-discharge cycle tests. FIG. 4 plots the average output voltage recovery in 20 charge-discharge tests against the carbonization temperature.

  It can be seen from FIG. 4 that the carbonization temperature is an important condition for producing a good positive electrode for an air secondary battery. In this experiment, the positive electrode carbonized from wood sawdust and palm sawdust needs to be carbonized in a temperature range of 700 ° C to 1350 ° C. In order to enable high-temperature carbonization, solidification by compression of wood / powder is likely. In this experiment, uniaxial pressure and shear pressure were solidified in the range of 4 to 250 atm. The optimum pressure value varies depending on the sawdust such as wood and coconut shells, and appropriate solidification is required within the above pressure range. In order to carry out a solid process on a large scale, the use of a rotation / extrusion apparatus will be practical.

  It was found that the upper limit of the carbonization temperature at which the output recovery rate of the secondary battery can ensure 95% or more is 1350 ° C., and the lower limit temperature is 700 ° C. The reason why the carbonization temperature characteristics are slightly different depending on the type of raw material of sawdust is considered to be due to the difference in the particle size of the material powder and the hardness when solid processed.

  The carbonization time varies depending on the amount of raw material sawdust and the carbonization temperature, and it is necessary to select an appropriate carbonization time suitable for the raw material.

  In short, it can be seen that an important point as the positive electrode of the air secondary battery is that the carbonization temperature is in the range of 700 ° C. to 1350 ° C.

<Processing shape of white charcoal cathode>
Since the production conditions of white coal were understood, experiments were conducted on the shape of white coal as a positive electrode. From the bulk type, white charcoal powder shape and powder were dissolved in a binder to produce a plate-like positive electrode that was ceramic processed at high temperature, and the characteristics of the secondary battery as a positive electrode were investigated. Table 1 summarizes the results of secondary battery characteristics of various types of white coal (powder, ceramic plate, etc.) and positive electrodes obtained by kneading white coal powder and activated carbon powder. The evaluated characteristics are the ratio between the charge capacity and the discharge capacity and the recovery rate of the weight of the negative electrode zinc. The test evaluated the average value in a 20 times charge-discharge cycle test.

From Table 1, it can be seen that ogashira coal functions as an excellent secondary battery positive electrode not only in the bulk type positive electrode but also in the shape of white charcoal powder, white charcoal-activated carbon powder mixture, or ceramic plate processing. This experiment is a useful finding in the production of a practical air secondary battery using white coal.

<N-molecule addition effect>
Below, the remarkable improvement effect of the positive electrode function by the addition of the nitrogen atom to the air secondary battery positive electrode carbonized from wood sawdust at 950 ° C. will be described based on the experimental results.
The positive electrode capacity of sawdust has been confirmed to be improved by 2-3% in the activation with normal steam and CO ₂ gas, but N (such as nitrogen (N) molecules (or nitrogen atoms) or BN The positive electrode function was confirmed to be improved by adding the compound to the carbon structure of white coal.

  The addition of N molecules (N atoms) to the white coal was performed in a discharge in a nitrogen atmosphere or in a direct current sputtering apparatus. All the additions are performed at room temperature for about 5 to 60 minutes at room temperature. The addition of N atoms was also performed with N compound and boron nitride (BN). In BN addition, it added by the method of the electron gun vapor deposition in a vacuum.

  The amount of N atom added to the carbon structure of white coal was evaluated by XPS analysis. In the sputtering method, when N is added for about 5 minutes, N atoms are bonded at a rate of several percent with respect to the number of surface carbon (C) atoms of the white coal, and when N is added for 60 minutes, N addition proceeds to about 30%. It was. BN deposition was performed in 5 minutes to 45 minutes. It has been verified that the deposition of BN on white coal improves the positive electrode capacity of the secondary battery, in particular, the function of improving the output voltage (50 mA discharge) during discharge to 40% or more.

  The N atom (molecule) effect added to the carbon structure is shown in FIG. The horizontal axis in FIG. 4 represents the adhesion ratio (%) of N atoms to C atoms determined by XPS after annealing for several minutes after N addition. The vertical axis represents the ratio (%) obtained by standardizing the discharge output voltage (50 mA) of the secondary battery in the case without N addition. It has been found that the N addition effect contributes significantly to the output improvement of the air secondary battery, whether it is N alone or a compound such as BN.

  A clear improvement in positive electrode capability is observed even in the region where the number of N molecules or the number of N atoms added to the carbon number is several percent. When the N addition rate is further increased, the positive electrode capacity is improved to about 140% at the maximum. Although the conditions for N addition (temperature, N addition process, etc.) have not been optimized, further improvement of the function can be expected up to about 150% by further selecting the conditions.

  The N addition treatment to the white coal can be said to be an important property of the white coal positive electrode that exerts its power in an air secondary battery or the like that requires a large current operation. In addition, unlike the expensive catalyst such as Pt, the N molecule to be added does not hinder low-cost production, which is a feature of the present air secondary battery.

  It is of course possible to add Pt or the like to further improve the capacity of the present white coal positive electrode, but the present white coal positive electrode has a practical level of battery positive electrode capacity as it is, but a small amount of Pt. It should be noted that a significant positive electrode function improvement can be realized by the addition of a catalyst.

Hereinafter, an explanation will be given regarding an air secondary battery using an oxygen electrode in which a hydrogen storage alloy is used for the negative electrode and the present invention is mixed with sawdust and NiOOH.
The basic structure of this battery is shown in FIG. In this battery, H ⁺ ions are released from the hydrogen storage alloy of the negative electrode (Pd is used in the experiment), and OH ⁻ ions use external oxygen gas and OH ⁻ ions accumulated in the white coal.

  Here, it is necessary to efficiently perform electrolysis of water, and the function is assumed to be NiOOH kneaded into white coal. By supplying oxygen in the air to the positive electrode (white coal and NiOOH) from the outside, new OH ions are generated, thereby enabling an air secondary battery having excellent charge / discharge cycleability.

FIG. 7 shows the results of up to four cycle tests, and the battery output recovery rate is 99%. In this cycle test, the recovery rate of H ⁺ ions is important, but a recovery rate of 98% or more was verified in 20 cycle tests.

  This air secondary battery is excellent as a practical secondary battery because the negative electrode is a hydrogen electrode and a large capacity battery is also possible. The characteristics of the two types of air secondary batteries (zinc negative electrode, hydrogen negative electrode) have been described. In the following, these battery modules, combined battery systems connected to other power sources such as solar cells, and the like The industrial application of will be described.

<Composite battery system by connecting air secondary battery and solar battery>
The air secondary battery of the present invention is low-cost and mass-produced, and has a feature that a large-capacity air secondary battery can be manufactured. This rechargeable / dischargeable air battery is a useful battery as a single battery, but it is possible to construct a reproducible battery system excellent in the environment by being connected to a solar battery or the like.

  FIG. 8 shows an example of a composite battery system in which solar battery modules are connected as a charging device for the air secondary battery module. In this composite battery system, the time-varying current output from the solar battery can provide a stabilized current output to the load through a process of charging the air battery. In addition, it is possible to supply a stable current to the load from the charged air secondary battery even when the sunlight is low or at night. The electronic control switch unit shown in FIG. 8 has a function of appropriately controlling the timing of charging from the solar battery and the output from the air battery to the load.

  Here, an example of the basic configuration of the composite battery system is shown. Depending on the type of load, a simple secondary battery module such as a Ni-H or Li-ion battery is added to the lower stage of the air battery, so that it can be further applied. A highly efficient composite battery system becomes possible.

  Taking advantage of the excellent charge-discharge characteristics of air rechargeable batteries and high capacity at low cost, the supply-storage-distribution of various power sources that are currently under development on a global scale It can be applied as a smart grid power source and a large-capacity charging device that are controlled by a power source.

  In addition to commercial power, the power sources of this network include large and small power sources with different scales, such as solar power generation and wind power generation, etc., but using the features of this air secondary battery, it is suitable for various power sources. Air secondary battery modules with large, medium and small capacities are possible.

  As a charging / discharging device of various power sources, a smart grid that enables efficient and stable power supply can be realized by using together with other excellent batteries such as a Pb storage battery.

As described above, the details of the experiment relating to the present invention and the excellent charge-discharge characteristics have been described in which the negative electrode metal is zinc and the electrolytic solution is NH ₄ Cl system. It goes without saying that the liquid is not limited.

  Moreover, although the structure of the composite battery system which connected the solar cell as a charging source was shown, cooperation with various power supplies other than a solar battery is possible, and the composite battery system is an LED lighting device and an illumination device. It should also be noted that it has a very wide range of applications, such as various types of lighting power supplies for disaster prevention.

Claims (7)

  Using wood, shards of wood, sawdust, coconut, etc., sawdust, shards, and small chips as raw materials, processing them into a solid, and then carbonizing the solid at a temperature of 700 ° C to 1350 ° C A method for producing a positive electrode material for an air secondary battery.   A positive electrode material for an air secondary battery composed of a bulk shape cut out from carbonized “oga white coal”, a powder of ogashira coal, or a plate shape obtained by ceramic processing from powder, and an air secondary battery using the same.   The positive electrode material of the air secondary battery comprised by mixing the activated carbon excellent in electrical conductivity and oxygen adsorption capacity, and the air secondary battery using the same.   The positive electrode of the air secondary battery in which the positive electrode capacity is improved by adding nitrogen molecules or nitrogen atoms to the "oga shirako" according to claim 1-3 by discharge in a nitrogen gas or a sputtering apparatus, and the like, and Air secondary battery by it.   The air battery comprised with the positive electrode material of Claim 1-4, The air secondary battery which uses hydrogen electrodes, such as a hydrogen storage alloy, for a negative electrode.   A configuration in which the module of the air secondary battery according to claim 1-5 and a module such as a solar cell complement each other's battery output, or the solar cell as a charging source for the air secondary battery Combined battery system.   The module of the air secondary battery according to any one of claims 1 to 5, or various lighting devices, an illuminating device, a disaster prevention device, and a power supply device for various electronic devices by a combined battery system connected to a solar cell or the like .

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