PowerBanks "How It Works" : 10 Steps (with Pictures) - Instructables

Lithium-ion batteries use a variety of cathodes and electrolytes. Common combinations use an anode of lithium (Li) ions dissolved in carbon or graphite and a cathode of lithium cobalt-oxide (LiCoO2) or lithium manganese-oxide (LiMn2O4) in an liquid electrolyte of lithium salt. Because they use a liquid electrolyte, lithium-ion batteries are limited in shape to either prismatic (rectangular) or cylindrical. The cylindrical form has a similar construction to other cylindrical rechargeable batteries,Prismatic batteries have the anode and cathode inserted into the rectangular enclosure. The image link at illustrates this construction method. Lithium-Ion-Polymer batteries are the next stage in development and replace the liquid electrolyte with a plastic (or polymer) electrolyte. This allows the batteries to be made in a variety of shapes and sizes. The significant advantages of lithium-ion batteries are size, weight and energy density (the amount of power the battery can provide). Lithium-ion batteries are smaller, lighter and provide more energy than either nickel-cadmium or nickel-metal-hydride batteries. Additionally, lithium-ion batteries operate in a wider temperature range and can be recharged before they are fully discharged without creating a memory problem. As with most new technology, the disadvantage is pricing. Currently, lithium-ion and lithium-ion-polymer batteries are more expensive to manufacture than standard rechargeable batteries. Part of this expense is due to the volatile nature of lithium. Lithium-ion batteries are most commonly used in applications where one or more of the advantages (size, weight or energy) outweigh the additional cost, such as mobile telephones and mobile computing devices. Lithium-ion-polymer batteries are used when the battery needs to be a particular shape. ________________________________________ Lithium-Ion Battery Characteristics Type Secondary •Chemical Reaction Varies, depending on electrolyte. Operating Temperature 4∫ F to 140∫ F ( -20∫ C to 60∫ C) •Recommended for Cellular telephones, mobile computing devices. •Initial Voltage 3.6 & 7.2 Capacity Varies (generally up to twice the capacity of a Ni-Cd cellular battery) •Discharge Rate Flat •Recharge Life 300 - 400 cycles •Charging Temperature 32∫ F to 140∫ F (0∫ C to 60∫ C) •Storage Life Loses less than 0.1% per month. •Storage Temperature -4∫ F to 140∫ F ( -20∫ C to 60∫ C) ï The chemical construction of this battery limits it to a rectangular shape. ï Lighter than nickel-based secondary batteries with (Ni-Cd and NiMH). ________________________________________ Lithium-Ion-Polymer Battery Characteristics Type Secondary Chemical Reaction Varies, depending on electrolyte. Operating Temperature Improved performance at low and high temperatures. Recommended for Cellular telephones, mobile computing devices. •Initial Voltage 3.6 & 7.2 •Capacity Varies depending on the battery; superior to standard lithium-ion. •Discharge Rate Flat •Recharge Life 300 - 400 cycles •Charging Temperature 32∫ F to 140∫ F (0∫ C to 60∫ C) •Storage Life Loses less than 0.1% per month. •Storage Temperature -4∫ F to 140∫ F ( -20∫ C to 60∫ C) ï Lighter than nickel-based secondary batteries with (Ni-Cd and NiMH). ï Can be made in a variety of shapes.