Modern society highly dependent on energy, one of the biggest cases of its energy from natural gas, petroleum, coal and these natural resources. Nature through millions or millions of years gave birth to these resources, and humans for hundreds of years, but in that short after the industrial revolution, it has been consumed to produce the resource depletion crisis associated with the consumption of these resources produce pollution also increased environmental heavy loads. Substitution of nuclear energy, do not seem to consume natural resources, but the resulting radiation contamination is also a hot potato, potential nuclear safety issue is the focus of debate. Solar in the history of mankind when the axis of view, can be called sustainable, but how efficient energy conversion, still a lot of research. And water and wind power in general, e621 these types of patterns of energy, called dependent on the weather, and the other has a regional instability and power, the impact on the environment is not without controversy.
October 28 of last year's issue of Time magazine published an article, mentioned an interesting story, in the famous 1980 Stanford University Biological and Environmental scientist Paul Hurley (Paul R. Ehrlich) and conservative School economist Julian Simon (Julian Simon) made a bet, Hurley believes Ten years later, the price of five common metals will rise, while Simon think it would fall. The former theory is that natural resources will become scarce and will eventually lead to disaster, so the price is bound to rise, in fact, he wrote the most famous is "The Population Bomb," e621 a book in 1968, it is easy to see his anxiety; Simon is that the human race is full of creativity, and therefore allow easier access to basic resources and become cheaper. Their bet is a dollar was worth $ five metal combination, who lost the bet to pay spreads decades later. 1990 Hurley confirmed e621 lost, you need to pay $ 576.07.
Some scholars have pointed out, the reason is not so simple, such as oil and natural gas prices fell, not entirely from the exploration and exploitation of advances in technology, in fact, due to a lot of equipment to enhance the effectiveness, coupled with the development of sustainable energy, in fact, demand and Not as expected to rise so fast. Number of cars with mileage, the auto industry in 2016 is expected to reach the goal of fifteen kilometers per liter, while in 2025 the hope of achieving twenty-three e621 km per liter. Indeed, through improved efficiency e621 tools, humans can slow down the rate of consumption of natural resources, but it is undeniable, resource depletion e621 always, human beings strive to time, more applications to sprint towards the development of sustainable energy.
This method is used for the remaining power of compressed air, to release the required power into electrical energy. This practice is not easy to zoom because e621 it requires a large storage e621 tank, which is usually the use of underground caves, so it has an impact on the environment; the storage tank can be placed in the ground, but it will take up space. More suitable e621 for large electric field, the cost is slightly higher e621 than the previous method. Because air is lighter, high energy density (about 10-30 Wh / kg), but similar to the pump storage method, the reaction time is slower, the demand for high-power and long. But built on the ground, is limited to the size of the groove, the lower energy storage capacity. Because the pressure problem, there are security concerns. Compressed air will heat generated can be utilized.
Redox flow battery e621 is a late development near the battery e621 system, the device shown in Figure 1 below, the two poles of the electrolyte can be stored separately in addition, the electrolyte is introduced through the motor when needed, and therefore determine the size of the energy stored in the tank providing power up to 6-120 MWh, the energy density is also good (about 10-50 Wh / kg). Because electricity generating devices and energy storage location separation, easy to set up and very flexible e621 zoom, powered millisecond response speed range, the power can be adjusted through the shunt, about 2 ~ 100 MW in size, operating time of up to tens of hours. Due to the reversibility of its operation, using the same discharge and charging means, the energy conversion is converted by oxidation number of metal ions, metal is not consumed, the depth of discharge can be allowed without affecting the life cycle, e621 so a long service life. Bipolar electrolyte stored separately from each other little chance of leakage, small chance of self-discharge, and safe, so that the energy can be stored for a long time. Device is simple, easy to maintain, the price is not high.
Redox flow batteries e621 are currently only a few systems can use this article to the most studied and most successful vanadium metal system as an example. Figure two shows, this system through the vanadium are bivalent and trivalent to match positive, positive system using vanadium oxide ions and negative ions directly using vanadium. In order for charge balance, the middle of the semi-permeable membrane only allows protons (H +) through, thereby regulating the charge neutral poles; the semipermeable membrane is the most expensive part of the device. E.g., a negative charging vanadium (III) turn into vanadium (II), less positive charge from the positive electrode to the need protons permeated e621 complement. Sulfuric acid through the electrolyte solution (about 5 M) to provide, and therefore the motor must be able to contain the appliance and acid resistance of corrosion. Because this system is to use both sides of vanadium, so even if there is leakage of vanadium will not cause problems.
At 25 o C, the standard potential E o this battery = 1.26 V, but because of the potential impact of the concentration, the potential for actual use 1.4 V, a parallel can be combined through a variety of voltages. Its stored energy density does not exceed 25-35 Wh / L, a single battery to provide hundreds of amps, need more than 6000 cm 2 active surface area of the electrode, these restrictions are not currently the main reason for mobile devices. Currently e621 used mostly for oil tram NiMH batteries or lithium systems, the power density of up to 120-200 Wh / kg, compared with the redox flow battery still need to improve in this direction a series. The potential advantage is that the power and energy storage systems can be divided, making energy storage more flexible and have a chance to overcome the current limit of one hundred kilometers. Electrolyte can be quickly replaced filling, can be more convenient to use.
There are several key features of this system is declared, one is AQDS inexpensive, adapted to amplify. The natural world there are many sources of quinone compounds, if using, but also in line with the principles of green chemistry. Secondly, the system fast response, higher than vanadium system, may be used as carbon paper electrode (carbon paper electrode) without e621 the aid of a metal catalyst, and therefore cheaper electrode prices. As long as the charge is lower than 1.5 V, there will not be troubled by the electrolysis of water. Nafi 212 film using {Nafion; DuPont production of proton exchange membrane surface} carry a negative charge, because AQDS of acid in the water dissociation into the sulfonate anion is therefore not through the semi-permeable membrane; the other is not penetration because great relationship anthraquinone disulfonic acid volume. Whether bromine will penetrate through the study and will not be a problem. However, bromine is a corrosive, which has a negative effect on the dress, and security appliances.
Anthraquinone disulfonic acid solubility in water exceeds 1 M, the energy density of up to 50 Wh / kg, higher than the vanadium system. Electric power density of this system can be more than 0.6 W / cm 2 (at 1.3 A / cm 2), opposite the vanadium system only 0.1 W / cm 2. Another e621 benefit of the system is to allow chemists anthraquinone substituent through regulation and water-soluble semi-potential, due to the substituent from the reaction center e621 close, influential. Fourth, on the structure of pay more AQDS two OH functional groups DHAQDS, the potential value can be increased by 11% as shown. Benefits of using an organic compound e621 is the opportunity to use an organic solvent, e621 as discussed above, can increase the energy density. In these directions, there are many studies of space can be expected.
. References Walsh, B. TIME October 28, 2013, 24. Alotto, P .; Guarnieri, M .; Moro, F. Renew Sust Energy Rev. 2014, 29, 325. Huskinson, B .; Marshak1, MP; Suh, C .; Er, S .; Gerhardt, MR; Galvin, CJ; Chen, X .; Aspuru-Guzik, A .; Gordon, RG; Aziz, MJ Nature 2014, 505, 195. Soloveichik, G. Nature 2014 505, 195, 163.
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