batteries Pode ser divertido para qualquer um
batteries Pode ser divertido para qualquer um
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For instance, energy can be stored in Zn or Li, which are high-energy metals because they are not stabilized by d-electron bonding, unlike transition metals. Batteries are designed so that the energetically favorable redox reaction can occur only when electrons move through the external part of the circuit.
Manufacturers often publish datasheets with graphs showing capacity versus C-rate curves. C-rate is also used as a rating on batteries to indicate the maximum current that a battery can safely deliver in a circuit. Standards for rechargeable batteries generally rate the capacity and charge cycles over a 4-hour (0.25C), oito hour (0.125C) or longer discharge time. Types intended for special purposes, such as in a computer uninterruptible power supply, may be rated by manufacturers for discharge periods much less than one hour (1C) but may suffer from limited cycle life.
Batteries can act as a pushing force to push the electrons through a component to make it work. Batteries can only act as the pushing force for a limited amount of time, this depends on how much charge the battery has and also how much energy is demanded by the load.
The battery produces electrical energy on demand by using the terminals or electrodes of the battery. The positive terminal is located on the top of the battery which is used for customer interests such as flashlights and electronics.
The fundamental relationship of electrochemical cell operation, put forth by the English physicist-chemist Michael Faraday in 1834, is that for every ampere that flows for a period of time, a matching chemical reaction or other change must take place. The extent of such changes is dependent on the molecular and electronic structure of the elements constituting the battery electrodes and electrolyte. Secondary changes may also occur, but a primary pair of theoretically reversible reactions must take place at the electrodes for electricity to be produced. The actual energy generated by a battery is measured by the number of amperes produced × the unit of time × the average voltage over that time.
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.
Many types of batteries employ toxic materials such as lead, mercury, and cadmium as an electrode or electrolyte. When each battery reaches end of life it must be disposed of to prevent environmental damage.
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.
Electrons move through the circuit, while ions simultaneously move through the electrolyte. Several materials can be used as battery electrodes. Different materials have different electrochemical properties, so they produce different results when assembled in a battery cell.
The casing of batteries is made from steel, and the rest of the battery is made from a combination of materials (listed above) dependent on type and application. The rest of the cell is made from a combination of paper and plastic.
It is a type of lead-acid battery in which the sulfuric акумулатори acid electrolyte is condensed (thickened), so it cannot drain out. They are somewhat sealed but have vents if the gases are accidentally released by overcharging. This battery is designed to last up to 12 years.
The voltage of an individual cell and the diffusion rates inside it are both reduced if the temperature is lowered from a reference point, such as 21 °C (70 °F). If the temperature falls below the freezing point of the electrolyte, the cell will usually produce very little useful current and may actually change internal dimensions, resulting in internal damage and diminished performance even after it has warmed up again.
These rechargeable batteries have two electrodes: one that's called a positive electrode and contains lithium, and another called a negative electrode that's typically made of graphite. Electricity is generated when electrons flow through a wire that connects the two.
Secondary batteries use electrochemical cells whose chemical reactions can be reversed by applying a certain voltage to the battery.