Keywords: electrochemistry; Life in a new era; Future development;
First, what is electrochemistry?
As a branch of chemistry, electrochemistry is a science that studies the changes of electrification and electron transfer at the interface formed by two conductors (electronic conductor, such as metal or semiconductor, ionic conductor, such as electrolyte solution). Traditionally, electrochemistry mainly studies the mutual transformation between electrical energy and chemical energy, such as electrolysis and galvanic cells. However, electrochemistry is not limited to the chemical reaction of electric energy, but also includes other physical and chemical processes, such as electrochemical corrosion of metals and metal replacement reaction in electrolyte solutions. The wide application of electrochemistry in the new era has brought great convenience to life.
Among many branches of physical chemistry, electrochemistry is the only subject based on large industry. Its applications mainly include: electrolysis industry, in which chlor-alkali industry is an inorganic basic industry second only to synthetic ammonia and sulfuric acid; Electrolysis is also used to smelt light metals such as aluminum and sodium, and to extract copper and zinc. The mechanical industry uses electroplating, electropolishing and electrophoretic coating to finish the surface processing of parts. Environmental protection can remove pollutants such as cyanide ions and chromium ions through electrodialysis; Chemical power supply; The corrosion prevention of metals is mostly electrochemical corrosion; Many life phenomena, such as muscle movement and nerve information transmission, involve electrochemical mechanism. Various electrochemical analysis methods developed by applying electrochemical principles have become indispensable means for laboratory and industrial monitoring.
Among many branches of physical chemistry, electrochemistry is the only subject based on large industry. Its application is divided into the following aspects: electrolysis industry, in which chlor-alkali industry is an inorganic basic industry second only to synthetic ammonia and sulfuric acid, and the intermediate monomer adiponitrile of nylon 66 is synthesized by electrolysis; Electrolysis is also used to smelt light metals such as aluminum and sodium, and to extract copper and zinc. The mechanical industry should use electroplating, electropolishing and electrophoretic coating to finish the surface finishing of parts; Environmental protection can remove pollutants such as cyanide ions and chromium ions through electrodialysis; Chemical power supply; The corrosion prevention of metals is mostly electrochemical corrosion; Many life phenomena, such as muscle movement and nerve information transmission, involve electrochemical mechanism; Various electrochemical analysis methods developed by applying electrochemical principles have become indispensable means for laboratory and industrial monitoring.
Second, the application of nanotechnology.
Min 'an talked about the application of nanotechnology in lithium-ion batteries. My first thought is LiFePO4. In order to improve its conductivity, people prepared it into nanoparticles, which greatly improved the electrochemical performance of LiFePO4. In addition, silicon anode is also a beneficiary of nanotechnology. Nano-silicon particles can well inhibit the volume expansion of Si during lithium intercalation and improve the cycle performance of Si materials.
Recently, Jun Lu of Argonne National Laboratory published an article in Nature Nanotechnology, summarizing and reviewing the application of nanotechnology in lithium-ion batteries.
So is the electric light. The steam lamp invented by human beings can actually be "dazzling". A steam lamp can illuminate the area around ten meters. Before there were electric lights, street lamps in Britain were steam lamps. The problem is not brightness. It is very inconvenient to use. Every time the steam lamp is turned on and off, people need to climb onto the lamp post to operate it. The operability and controllability of electric lamps are better than those of steam lamps. Today, we watch TV. In fact, movies can be said to have no electricity at all. In the early days, kerosene lamps or gas lamps were used to show the film, and the film could be rotated manually.
Early phonographs (not record players) used clockwork instead of electricity. Therefore, even without electricity, we can watch and listen to entertainment programs. There is a solution.
If it weren't for the development of electronic technology, in the era without modern electric energy, it would be difficult to find substitutes except what computers can do today (smart phones are also a kind of computers). And ordinary daily necessities, even early hand-held phones, are powered by hand-cranked generators and dry batteries, which are also divorced from electric energy in the modern sense (there is no grid power supply). In other words, if the cost is not considered, 90% of our living needs can be met without modern power supply.
The application of electrochemical corrosion protection, according to the knowledge of cathodic protection/electrochemical corrosion protection/drainage protection in electrochemistry, the electrochemical corrosion performance of cemented carbide was studied mainly by leaching method and electrochemical testing method in the laboratory. The electrochemical method mainly obtains the polarization curve of cemented carbide samples by potentiodynamic scanning, and then obtains the corrosion potential, corrosion current density, critical current density, minimum current density and other parameters in the passivation interval to evaluate the corrosion performance of cemented carbide.
According to the characteristics of electrochemical corrosion behavior of materials, metal materials can be divided into active metal materials that actively dissolve in corrosive media and inactive metal materials that can form protective films on their surfaces. In view of the above two materials, electrochemical testing technology and surface analysis technology were used to discuss the influence of surface nanocrystallization on the electrochemical corrosion behavior of materials in acidic medium.
Among all ship systems, seawater system is the worst working environment, and its circulating medium is seawater, which is one of the most corrosive natural corrosives. Therefore, pipelines, valves and equipment in seawater system are most vulnerable to electrochemical corrosion. Common anti-corrosion methods include: adding sacrificial flanges or sacrificial tubes where different metals contact to weaken the effect of electrolyte solution and neutralize the effect of negative ion solution in seawater; Non-metallic materials or metal materials with the same potential are used, which are not easy to corrode; The most common method on board is to cut off the communication between different metals.
Hydrogen fuel cell is an energy conversion device, which converts the electrochemical energy of fuel into electrical energy. It is also an electrochemical power generation device like a battery, so it is called a fuel cell. The corresponding fuel cell using hydrogen as fuel is a hydrogen fuel cell. It can be understood as the reverse reaction of water electrolysis into hydrogen and oxygen. Therefore, the reaction process is clean and efficient. Because it is not limited by the thermal efficiency of about 42% of the traditional Carnot cycle. The efficiency of hydrogen fuel cells can easily reach more than 60%.
As an efficient energy storage element, lithium-ion battery has been widely used in the field of consumer electronics from mobile phones to notebook computers. Li-ion battery has made such brilliant achievements thanks to its ultra-high energy storage density and good safety performance. With the continuous development of technology, the energy density and power density of lithium-ion batteries are also increasing, among which nanotechnology has made an indelible contribution.