The factors considered are specific energy, specific power, safety, performance, life span, and cost. In these spider diagrams, batteries that are better suited for EVs have a larger colored area. The next figure includes spider diagrams comparing the basic types of Li batteries based on their suitability for use in electric vehicles (EVs). They can provide large amounts of power in a small package but can be more susceptible to thermal events that can cause safety issues. Note that the NMC, LCO, and NCA batteries contain Cobalt that helps to provide higher power capabilities. LTO – 80Wh/kg, lowest specific energy, but can be fast charged, discharged at up to 10-times its rated capacity, and is safe.Ĭomparison of lithium battery voltages and applications.Because of its flexibility, it is one of the most successful lithium battery chemical systems. NMC – 200Wh/kg, varying the proportions of the chemical constituents allows the development of batteries optimized as power or energy cells.NCA – 250Wh/kg, offers high specific energy and long cycle lives.
LMO – 140Wh/kg, cathodes are based on manganese-oxide components that are abundant, inexpensive, non-toxic, and provide good thermal stability.LFP – 120Wh/kg, have long cycle lives and stability at high operating temperatures.LCO – 200Wh/kg, deliver a high power, but with the tradeoff of relatively short lives, low power ratings, and low thermal stability.Other characteristics of these batteries include: The table below compares the voltages and typical applications of the six basic lithium battery chemistries. It can also cause structural damage to the host system. This expansion can be particularly noticeable for LiPos, which can literally inflate. Vaporization of the electrolyte can cause delamination, causing bad contacts between the internal layers of the cell, reducing reliability and cycle life. Like Li-ions, LiPos can expand at high levels of overcharge due to the vaporization of the electrolyte. In addition, crushing or nail penetration of the LiPo pouches can result in catastrophic failures ranging from pouch ruptures to electrolyte leaks and fires. The use of LiPos is subject to many of the same challenges that users of Li-ion must contend with, including overcharging, over-discharging, over-temperature operation, and internal shorts. Lithium polymer battery pouch construction. The case is sealed using a laser welding process. But it is also robust, helping to protect the battery from damage. The case is relatively costly to produce and tends to restrict the sizes and shapes that are available. The case is most often cylindrical but can be button-shaped or rectangular (prismatic). Li-ions are usually delivered in a stainless steel or aluminum case. However, they are packaged in quite different ways. Except for the polymer separator, LiPos operate on the same principle as Li-ions. The intercalation and decalation of lithium ions from a positive electrode and a negative electrode. Shutdown separators are multilayer structures with at least one polyethylene layer which can stop current flow when the temperature rises too high and at least one polypropylene layer which acts as a form of mechanical support for the separator. In addition, polymer separators can provide an additional function acting as “shutdown separators” that can shut down the battery if it becomes too hot during charging or discharging. In a LiPo, the polymer separator also contains the electrolyte. It closes with a look into the future and the possible development of aluminum-air polymer batteries and solid-state batteries.Īll lithium batteries include a barrier to separate the anode and cathode while also enabling the movement of ions between the electrodes. This FAQ begins with a high-level comparison of Li-ion and LiPo batteries, followed by a detailed look at the six basic lithium battery chemistries most suitable for use in LiPo batteries. LiPos provide higher specific energies than other lithium batteries, often used in systems where weight is an important factor, such as mobile devices, drones, and some electric vehicles. All use a high conductivity gel polymer as the electrolyte. There are a variety of LiPo chemistries available. A lithium-ion polymer (LiPo) battery (also known as Li-poly, lithium-poly, PLiON, and other names) is a rechargeable Li-ion battery with a polymer electrolyte in the liquid electrolyte used in conventional Li-ion batteries.
0 kommentar(er)
