Portable power station energy storage battery type

　　Optional energy storage portable power stations batteries include: sodium-sulfur batteries, flow batteries, lead-acid batteries, lithium iron phosphate batteries and power capacitor batteries. The introduction of various types of batteries is as follows:

　　(1) Sodium-sulfur battery

　　The sodium-sulfur battery works in a high temperature environment of 300 ° C. Its positive active material is liquid sulfur (S); the negative active material is liquid metal sodium (Na), and the middle is a porous ceramic separator. The main features of sodium-sulfur batteries are high energy density (3 times that of lead capacitor batteries), high charging efficiency (up to 80%), and longer cycle life than lead capacitor batteries. They are suitable for large-scale energy storage systems.

　　(2) Flow battery

　　The active material of the flow battery can be dissolved and distributed in two storage tanks. The solution flows through the flow battery, and reduction and oxidation reactions occur on the electrodes on both sides of the ion exchange membrane. This chemical reaction is reversible, so the ability to charge and discharge multiple times can be achieved. The energy storage capacity of this system is determined by the volume of electrolyte in the storage tank. There are many systems such as vanadium-bromine, all-vanadium, and sodium polysulfide/bromine for flow batteries.

　　(3) Lead-acid battery

　　The main feature of the lead-acid capacitor battery is that it uses dilute sulfuric acid as the electrolyte, and uses lead dioxide and velvet lead as the positive and negative electrodes of the battery, respectively. It has the advantages of low cost, mature technology, and large energy storage capacity. , Mainly used in power system backup capacity, frequency control, uninterruptible power system. However, its disadvantages are low storage energy density, few rechargeable and discharge times, and certain pollution in the manufacturing process.

　　(4) Lithium iron phosphate battery

　　Lithium-ion batteries have high working voltage and fast response speed, but are large in size and have average energy storage density. Lithium iron phosphate battery is a kind of lithium ion battery, and its cathode material is lithium iron cobalt phosphate LiFeCoPO4. Compared with traditional lithium cobalt oxide batteries, the energy density of iron batteries is 75% of that of lithium cobalt oxide batteries, but it has advantages in terms of manufacturing cost, safety performance, cycle life, and power output range.

　　(5) Nanotechnology power capacitor battery

　　Power capacitor battery is a new type of green and environmentally friendly energy storage power product that uses nanotechnology and combines physical capacitors and chemical power sources. The power capacitor battery stores energy at the interface between the electrode material and the electrolyte, and has an ultra-high capacitance value, great charge and discharge power, and very good low temperature performance.

Helper for vacuum cleaner cleaning and care

　　The dust in the air covered all corners of the room; and these corners are beyond the reach of traditional cleaning tools, which is really an annoyance; in addition, there are pet hair, confetti on clothes, and shell scraps in the mini cordless car vacuum cleaner. , The food crumbs that my friends fell on the sofa, and the soot on the keyboard are all annoyances.

　　Cleaning up small paper scraps, nut shells and other garbage always wastes a lot of time. Household issues such as pet hair, water stains, and difficult to clean edges and corners have always plagued us. Nowadays, vacuum cleaners are enough for household cleaning, dry and wet. The three-purpose blowing function effectively sucks away solid, liquid and other garbage, and the strong suction can quickly dry the wet ground, which can be done from the kitchen to the balcony.

　　The principle of the vacuum cleaner is a process of sucking the air mixed with dirt into the dust bin through vacuum negative pressure, and then separating the clean air from the dust. There will be no dust and no secondary pollution.

　　The principle of the broom is that the big dirt is swept into the dustpan, and the fine dust is mixed into the air and distributed evenly, creating conditions for the production of pneumoconiosis. Hehe, although a bit alarmist, this is the main difference between a vacuum cleaner and a broom.

　　With the advancement of science and technology, more and more technology products that liberate human hands and feet have also appeared. People use cars instead of walking, phones instead of flying pigeons to pass books, and even use robots to help us clean the floor. With so many convenient electronic products, we don’t even need to clean the ground in the future.

The Science of the Summer Olympics

　　

　　The games are (finally) underway in Tokyo, and for the next two weeks, we'll witness the greatest display of sport physics at work.

　　After a year-long delay (and what a year it was!), the Tokyo Olympics are here finally here. For two weeks, the world's best athletes will put on incredible displays or skill, fortitude, stamina, and physics. Yes, physics.

　　To be the very best, athletes break down their sport to a science. Momentum is translated to joules, runners understand the intricacies of different muscle fibers, kayakers deftly navigate the math behind fluid dynamics. Here we break down some of the interesting science that'll be on display in the next two weeks.

　　Much has been written about the superhuman athletic ability of swimmer Michael Phelps. He’s a genetic wonder, built like a fish, with hands and feet like canoe paddles. All this is true—it is impossible to win at the Olympics without a genetic predisposition to your sport. Team USA at the Tokyo 2020 Olympic Games will be hoping to surpass—or at the very least imitate—what made Phelps a swimming phenomenon.

　　Body: Phelps’s body is a famously specialized swimming machine. His wingspan, at 6 ft. 7 in., is 3 in. longer than his height. And his long torso and relatively short legs—he has an inseam of 32 in.—let him ride high in the water.

　　Biochemistry: Strokes such as the butterfly tend to build up lactic acid in muscles, reducing their ability to perform. Phelps’s exact numbers are kept secret, but tests suggest that he naturally produces far less lactate than most athletes do.

　　Flexibility: Some sports require strength (shot put); others, flexibility (gymnastics). Swimming requires both. Phelps’s flexible elbows, knees, and ankles allow him to move through water with minimal resistance.

　　Hydrodynamics: In a 200-meter freestyle race, a swimmer moving at 3.8 mph expends 290 kilojoules fighting his own drag. To combat this, Phelps adopted a streamlined swimming posture—head down, hips high.

　　Technique: Phelps was the master of the dolphin kick. By pushing off the wall and whipping his legs, he can swim faster than with a traditional stroke—gaining an advantage of half a body length over competing swimmers.

　　Training: Phelps trained every day of the year—4 hours in the pool, 1 hour on dry land. Since swimmers can burn about 1,000 calories per hour, Phelps’s diet tended to be relatively high in carbohydrates to avoid glycogen depletion.

　　At the 2008 Beijing games, Michael Phelps was in a dead heat with Serbian Milorad Čavić. Čavić appeared to touch the wall first, but Phelps was the first to exert the 6.6 pounds of pressure required to activate the touchpad. The result: a victory margin for Phelps of 0.01 second, which the Serbian team disputed. But a review down to 0.0001 second confirmed Phelps’s gold.