阅读说明：本技术 一种铝空气电池 (Aluminum-air battery ) 是由 王二东 李洋 高建新 陈长科 马冰 孙公权 于 2018-12-13 设计创作，主要内容包括：本发明公开了一种铝空气电池,具体涉及一种包含二元铝合金负极/电解质复合体系的铝空气电池。通过在纯铝中仅添加一种异价金属作为活化金属,在碱性电解液中添加锡酸盐作为析氢抑制剂,制备得到的铝合金在异价金属的活化作用下,电解液中锡酸盐能够被金属铝还原成金属锡并均匀沉积在铝电极表面,没有添加异价金属在铝基体中时,锡酸盐无法均匀沉积在铝电极表面。该体系中铝合金只需添加一种合金元素,以及电解液中添加锡酸盐,相比其他多元铝合金负极,性能优异(析氢抑制效率高达96％),制备简单,成本低廉。(The invention discloses an aluminum-air battery, and particularly relates to an aluminum-air battery containing a binary aluminum alloy cathode/electrolyte composite system. By adding only one kind of aliovalent metal as an activation metal in pure aluminum and adding stannate as a hydrogen evolution inhibitor in alkaline electrolyte, the stannate in the electrolyte can be reduced into metallic tin by metallic aluminum and uniformly deposited on the surface of an aluminum electrode under the activation action of the aliovalent metal in the prepared aluminum alloy, and the stannate cannot be uniformly deposited on the surface of the aluminum electrode when the aliovalent metal is not added in an aluminum matrix. The aluminum alloy in the system only needs to be added with one alloy element, and the stannate is added into the electrolyte, so that compared with other multi-element aluminum alloy cathodes, the performance is excellent (the hydrogen evolution inhibition efficiency is up to 96%), the preparation is simple, and the cost is low.)

1. An aluminum-air battery comprises a binary aluminum alloy negative electrode, an alkaline electrolyte composite system and an air cathode, and is characterized in that:

the aluminum alloy cathode is formed by only adding one aliovalent metal element into an aluminum matrix, and the aliovalent metal comprises lithium, sodium, potassium, magnesium, calcium, barium, zinc, tin or lead metal elements;

stannate is added into the alkaline electrolyte as a hydrogen evolution inhibitor.

2. The aluminum-air cell as recited in claim 1, wherein:

the hydrogen evolution inhibitor stannate comprises one or more than two of lithium stannate, sodium stannate, potassium stannate and calcium stannate; the molar concentration range of the stannate is 0.05-0.1 mol/L;

the alkali in the alkaline electrolyte comprises one or more of lithium hydroxide, sodium hydroxide and potassium hydroxide, and the concentration of the alkali in the alkaline electrolyte is 0.1-14 mol/L.

3. The aluminum-air cell as recited in claim 1, wherein:

adding one metal element of lithium, sodium, potassium, magnesium, calcium, barium, zinc, tin and lead into an aluminum matrix to form an aluminum alloy;

the adding mass range of lithium in the aluminum matrix is 0.05-0.5%; the adding mass range of sodium in the aluminum matrix is 0.05-0.3%; the adding mass range of potassium in the aluminum matrix is 0.05-0.3%; the adding mass range of magnesium in the aluminum matrix is 0.1-3%; the adding mass range of calcium in the aluminum matrix is 0.1-0.3%; the adding mass range of barium in the aluminum matrix is 0.1-0.42%; the adding mass range of zinc in the aluminum matrix is 0.1-6%; the adding mass range of tin in the aluminum matrix is 0.01-0.16%; the mass range of the lead in the aluminum alloy is 0.1-0.15%.

4. The aluminum-air cell as recited in claim 3, wherein:

the aluminum alloy can be prepared by a high-temperature smelting method: weighing particles of an intermediate alloy formed by an aluminum block and other required metal elements or other required metal elements and aluminum, putting the particles into a crucible of a high-temperature smelting furnace, heating, melting and fully stirring, pouring a molten liquid into a steel mould, cooling and solidifying, and then homogenizing the cast ingot at 500-600 ℃ for 1-24 hours;

if other required metal elements contain lithium, sodium, potassium or calcium, smelting under the inert gas protection atmosphere;

or the aluminum alloy can be prepared by a powder metallurgy method, weighing aluminum powder and powder of other needed elements, mechanically milling and mixing uniformly, carrying out hot extrusion on the powder at 500-600 ℃, and carrying out heat treatment on the hot extruded alloy for 1-24 hours at 500-600 ℃.

Technical Field

The invention belongs to the field of aluminum-air batteries, and particularly relates to a preparation method of a binary aluminum alloy cathode and electrolyte composite system.

Background

The aluminum/air battery is a chemical power supply taking metal aluminum and oxygen in air as reactive active substances, the negative electrode is generally an aluminum alloy plate, the positive electrode is an air electrode consisting of a waterproof layer, a diffusion layer, a catalytic layer, a current collector and the like, and the electrolyte is alkaline solution or neutral solution. The electrochemical equivalent of the aluminum is 2.98Ah/g, which is second only to lithium, and the oxygen of the anode active material is from air, so the aluminum/air battery has the characteristic of high specific energy. In addition, the metal aluminum has rich resources, safe use and non-toxic and recyclable reaction products, and is an ideal electrode material.

Aluminum/air batteries using alkaline electrolyte systems have potential applications in high power applications, such as backup batteries, underwater device drives, and electric vehicle power supplies. However, aluminum in alkaline solutions can undergo severe hydrogen evolution corrosion, generate hydrogen gas and heat, and reduce the current efficiency of aluminum. The method for inhibiting the hydrogen evolution corrosion of the aluminum anode in the alkaline electrolyte mainly has two aspects, on one hand, various alloy elements such as magnesium, tin, gallium, indium, lead, bismuth, zinc and the like are added into high-purity aluminum, and on the other hand, a corrosion inhibitor is added into the electrolyte, wherein the performance of the battery can be obviously improved by multi-element aluminum alloy, but the preparation is complex and the cost is high. At present, the disclosed patents include Al-Mg-Sn-Ga-Mn quinary alloy in CN 102820472A, the anode utilization rate is more than or equal to 94%, and the quaternary alloy Al-Sn-Bi-Mn in CN 104018018A, the current efficiency is only more than 55%, and the alloy needs to be added with three or more alloy elements. Although the process of adding corrosion inhibitor in electrolyte is simple, the effect is not obvious, so researchers propose a composite system of organic and inorganic electrolytes, wherein the alkaline aluminum battery composite corrosion inhibitor in patent CN 102088115A comprises five inorganic corrosion inhibitors of sodium stannate, indium hydroxide, sodium citrate, calcium oxide and zinc oxide, and two organic corrosion inhibitors of chitosan derivative and organic surfactant. The electrolyte of patent CN 101353798A includes five corrosion inhibitors of polypropylene viscous liquid, sodium stannate, indium hydroxide, calcium chloride and sodium fluoride. The corrosion inhibitor of patent CN 103633396A comprises two corrosion inhibitors of sodium thiosulfate and sodium stannate, and the corrosion inhibitor of patent CN 104505559A comprises seven corrosion inhibitors of zinc oxide, calcium oxide, bismuth oxide, gelatin, bone glue, organic surfactant and organic dye. The addition of multiple active agents increases the difficulty and cost of electrolyte preparation. The activation effect of the aliovalent metal is discovered, a binary aluminum alloy electrolyte composite system is provided for the first time, only one metal element needs to be added into the aluminum alloy, a hydrogen evolution inhibitor is added into the electrolyte, and the hydrogen evolution corrosion rate is obviously reduced under the synergistic effect of the alloy element and the hydrogen evolution inhibitor. Compared with multi-alloying or corrosion inhibitor addition in other patents, the cost is obviously reduced, and the preparation is simple.

Disclosure of Invention

The invention discloses an aluminum-air battery, particularly relates to an aluminum-air battery containing a binary aluminum alloy cathode/electrolyte composite system, and provides a preparation method of the binary aluminum alloy cathode/electrolyte composite system. The compact passive film on the surface of the aluminum metal prevents stannate in the electrolyte from depositing on the surface of the electrode. By adding an aliovalent metal into the aluminum matrix, the passive film generated on the surface of the alloy can generate anion vacancy, the activation energy of ion diffusion is reduced, the ion diffusion coefficient is improved, and the ion conductivity of the passive film is improved according to the Nernst-Einstein equation. Therefore, the method can promote the deposition reaction of stannate on the surface of the electrode, and can effectively and uniformly deposit the metal tin with high hydrogen evolution overpotential on the surface of the aluminum electrode, thereby effectively inhibiting hydrogen evolution corrosion. Compared with other inventions in the field, only one alloy element needs to be added into the aluminum cathode, and the aluminum cathode has the characteristics of simple preparation and low cost. The method is realized by the following technical method:

a preparation method of an aluminum alloy negative electrode/electrolyte composite system is characterized in that one of metal elements of lithium, sodium, potassium, magnesium, calcium, barium, zinc, tin and lead is added into an aluminum matrix, and stannate is added into an alkaline electrolyte.

The aluminum alloy can be prepared by a high-temperature smelting method, wherein lithium, sodium, potassium and calcium are required to be smelted under the protective atmosphere of inert gas. Weighing an aluminum block and other metal particles or intermediate alloy particles formed by other metal elements and aluminum according to a certain mass ratio, putting the intermediate alloy particles into a crucible of a high-temperature smelting furnace, heating, melting and fully stirring, pouring molten liquid into a steel mould, cooling and solidifying, and then homogenizing the cast ingot at 500-600 ℃ for 1-24 hours.

The aluminum alloy can be prepared by a powder metallurgy method, aluminum powder and other metal powder in a certain mass ratio are weighed and mixed uniformly by mechanical ball milling, the powder is subjected to hot extrusion at 500-600 ℃, and the hot extruded alloy is subjected to heat treatment for 1-24 hours at 500-600 ℃.

The mass addition range of lithium in the aluminum matrix is 0.05-0.5%; the mass addition range of sodium in the aluminum matrix is 0.05-0.3%;

the mass addition range of potassium in the aluminum matrix is 0.05-0.3%;

the mass addition range of magnesium in the aluminum matrix is 0.1-3%;

the mass addition range of calcium in the aluminum matrix is 0.1-0.3%;

the mass addition range of barium in the aluminum matrix is 0.1-0.42%;

the mass addition range of zinc in the aluminum matrix is 0.1-6%;

the mass addition range of tin in the aluminum matrix is 0.01-0.16%;

the mass addition range of lead in the aluminum alloy is 0.1-0.15%.

The hydrogen evolution inhibitor is stannate, and comprises one or more of lithium stannate, sodium stannate, potassium stannate and calcium stannate. The molar concentration range of the stannate is 0.05-0.1 mol/L, and when the concentration of the stannate is lower than 0.05mol/L, metal tin cannot be uniformly deposited on the surface of the aluminum cathode due to too low concentration of the stannate, and the hydrogen evolution inhibition effect is not achieved.

The reaction solution is alkaline solution, and comprises one or more of lithium hydroxide solution, sodium hydroxide solution and potassium hydroxide solution. The concentration range of the alkaline solution is 0.1-14 mol/L.

The aluminum alloy electrolyte system prepared by the method has simple components and low cost. Only one of the metal elements of lithium, sodium, potassium, magnesium, calcium, barium, zinc, tin and lead is added into the aluminum matrix, and the stannate is added into the electrolyte to play a remarkable role in inhibiting hydrogen evolution corrosion.

Detailed Description

The following examples illustrate the invention in further detail without limiting it. In which comparative example 1 used pure aluminum and an electrolyte to which no stannate was added, and the hydrogen evolution inhibition efficiency was determined to be 0, and comparative example 2 used pure aluminum and an electrolyte to which stannate was added. The hydrogen evolution inhibition efficiencies of the examples and comparative examples are shown in table 1.