Tudo sobre batteries
Tudo sobre batteries
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These include tripling global renewable energy capacity, doubling the pace of energy efficiency improvements and transitioning away from fossil fuels.
That represents the versatility of energy storage systems—better known as batteries—that scientists are developing today.
These are made in various sizes and capacities, from portable sealed to large fanned cells used for standby power and motor power. Smaller packs are used in portable devices, electronics, and toys, while larger packs are used in aircraft starting batteries and electric vehicles.
If the temperature is raised deliberately, faster discharge can be sustained, but this is not generally advisable, because the battery chemicals may evaporate or react spontaneously with one another, leading to early failure.
seis volts per cell cylindrical and button batteries; used in digital cameras, small appliances high energy density; supports high discharge rates; long shelf life; expensive lithium-manganese dioxide lithium anode-manganese dioxide cathode with organic electrolyte; 2.oito–3.2 volts per cell cylindrical and button batteries; used in digital cameras, small appliances high energy density; supports high discharge rates; long shelf life; expensive Secondary (rechargeable) batteries type chemistry sizes and common applications features lead-acid lead anode-lead dioxide cathode with sulfuric acid electrolyte wide range of sizes; used in automobiles, wheelchairs, children's electric vehicles, emergency power supplies cheapest and heaviest battery; long life; pelo memory effect; wide range of discharge rates Alkaline nickel-cadmium cadmium anode-nickel dioxide cathode with potassium hydroxide electrolyte common cylindrical jackets; used in power tools, cordless telephones, biomedical equipment excellent performance under heavy discharge; nearly constant voltage; best rechargeable cycle life; memory effect in some; cadmium highly toxic and carcinogenic if improperly recycled nickel-metal hydride lanthanide or nickel alloy anode-nickel dioxide cathode with potassium hydroxide electrolyte some cylindrical jackets; used in smoke alarms, power tools, cellular telephones high energy density; good performance under heavy discharge; nearly constant 1.2-volt discharge; pelo memory effect; environmentally safe Lithium lithium-ion carbon anode-lithium cobalt dioxide cathode with organic electrolyte most cylindrical jackets; used in cellular telephones, portable computers higher energy density and shorter life than nickel-cadmium; expensive; no memory effect
A battery's capacity is the amount of electric charge it can deliver at a voltage that does not drop below the specified terminal voltage. The more electrode material contained in the cell the greater its capacity. A small cell has less capacity than a larger cell with the same chemistry, although they develop the same open-circuit voltage.[49] Capacity is usually stated in ampere-hours (A·h) (mAh for small batteries). The rated capacity of a battery is usually expressed as the product of 20 hours multiplied by the current that a new battery can consistently supply for 20 hours at 20 °C (68 °F), while remaining above a specified terminal voltage per cell.
It can be used for high- and low-drain devices but can wear out quickly in high-drain devices such as digital cameras. These batteries have a higher energy density and longer life, yet provide similar voltages as zinc-carbon batteries.
It is a rechargeable battery used in everyday electronic devices such as smartphones, laptop computers, and portable power tools. In this type, the chemical reaction at the positive electrode is similar to that of a nickel-cadmium cell, with both using nickel oxide hydroxide.
The sealed valve regulated lead–acid battery (VRLA battery) is popular in the automotive industry as a replacement for the lead–acid wet cell.
Secondary batteries, also known as secondary cells, or rechargeable batteries, must be charged before first use; they are usually assembled with active materials in the discharged state. Rechargeable batteries are (re)charged by applying electric current, which reverses the chemical reactions that occur during discharge/use. Devices to supply the appropriate current are called chargers. The oldest form of rechargeable battery is the lead–acid battery, which are widely used in automotive and boating applications.
Next-generation batteries are needed to improve the reliability and resilience of the electrical grid in a decarbonized, electrified future. These batteries will store excess energy–including renewable energy–when it is produced and then release that electricity back into the grid when it’s needed.
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This technology contains liquid electrolyte in an unsealed container, requiring that the battery be kept upright and the area be well ventilated to ensure safe dispersal of the hydrogen gas it produces during overcharging. The lead–acid battery is relatively heavy for the amount of electrical energy it can supply. Its low manufacturing cost and its high surge current levels make it common where its capacity (over approximately 10 Ah) is more important than weight and handling issues. A common application is the modern car battery, which can, in general, deliver a акумулатори бургас peak current of 450 amperes.
When a battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the battery (e.g. through a built-in vent), leading to pressure build-up and eventual bursting of the battery case. In extreme cases, battery chemicals may spray violently from the casing and cause injury. An expert summary of the problem indicates that this type uses "liquid electrolytes to transport lithium ions between the anode and the cathode. If a battery cell is charged too quickly, it can cause a short circuit, leading to explosions and fires".