Paraffin wax and oleic acid have been discovered to make up good materials for battery electrodes, which could have applicability in electric cars and power storage systems. A team of Pacific Northwest National Laboratory (PNNL) researchers in Richland, WA, have discovered a technique that could turn materials otherwise unsuited for battery electrodes into ones that exceed even today’s most advanced.
The two substances encourage the growth of plate-like nanostructures of lithium-manganese phosphate and store 10 percent more energy than it is maximum theoretically possible for lithium-iron phosphate, considered to store the best energy density yet. LiFePO4 is used in electric cars, power tools and others.
Lithium-iron phosphate batteries have a crystalline structure, called “olivine”, which is far more stable than that of classic lithium ion batteries used in laptops and cell phones, which regularly only have a lifetime of about three years. Just like their older siblings, lithium-manganese phosphate batteries by far have a higher lifespan and charge-discharge cycles. Researchers say both types can withstand 30,000 charge cycles and last up to 50 years, because of their stable crystalline structure.
Because of their higher voltage, lithium manganese phosphate batteries should theoretically store 20 percent more energy than lithium iron ones. Past attempts at making this insulating material into an energy storage material have failed because they have required processing precursor materials in a liquid solution before creating solid battery materials – a process that’s too expensive for commercial production. The new method developed at PNNL eliminates this separate liquid-processing step, simplifying the process and making it compatible with existing manufacturing techniques.
To prepare the material, the researchers mix chemical precursors with paraffin wax and oleic acid. The wax and acid work together to cause the precursor materials to form crystals of a well-controlled size and shape without clumping up. The wax liquefies at the high temperatures used to process the material and acts as a solvent that replaces the separate liquid processing step used in earlier research.
Still, there one inconvenient to this type of battery: its size. That makes them not so ideal for mobile applications like electric/hybrid cars or laptops, but good enough for stationary cases, where size doesn’t matter that much, compared to costs and efficiency.