In an attempt to pick up the pace, the M.I.T. researchers coated the lithium
iron phosphate material with an ion conductor, which in this case was a layer of glasslike lithium phosphate.
Not exact matches
In crystalline form, vanadium pentoxide can take three positively charged lithium ions — three times more than
materials presently used in cathodes, such as lithium
iron phosphate.
«We probably know about 1 % of the properties of existing
materials,» he says, pointing to the example of lithium
iron phosphate: a compound that was first synthesized in the 1930s, but was not recognized as a promising replacement
material for current - generation lithium - ion batteries until 1996.
This illustration shows a battery electrode made of lithium
iron phosphate (left side of image) coated with carbon, and in contact with an electrolyte
material.
Bazant says researchers had not suspected, despite extensive research on lithium
iron phosphate, that the
material's electrochemical reactions might be limited by electron transfer between two solids.
«We took a basically great
material called lithium
iron phosphate [LiFePO4] and we tried to improve it further,» says study author Byoungwoo Kang, a graduate student in M.I.T.'s Department of
Materials Science and Engineering.
Arumugam Manthiram, a professor of
materials engineering at the University of Texas at Austin, has demonstrated that a microwave - based method for making lithium
iron phosphate takes less time and uses lower temperatures than conventional methods, which could translate into lower costs.
Indeed, lithium
iron phosphate has become one of the hottest new battery
materials.
New Lithium
Iron Pyrophosphate as Li - ion Cathode
Material; Highest Voltage Among Known
Iron - based
Phosphate Cathodes
Although it stores less energy than some other lithium - ion
materials, lithium
iron phosphate is safer and can be made in ways that allow the
material to deliver large bursts of power, properties that make it particularly useful in hybrid vehicles.
At slow rates of discharge, the
materials showed an impressive capacity: at 166 milliamp hours per gram, the
materials came close to the theoretical capacity of lithium
iron phosphate, which is 170 milliamp hours per gram.