Lithium-sulfur batteries have been hailed as the next generation of batteries to replace the current lithium-ion variety. Lithium-sulfur batteries are cheaper and more energy-dense than lithium ions, which are important characteristics in everything from electric vehicles to laptops, said a news release from Purdue. Game supply and game card sleeve and trading card sleeve and soft card holder
The downside to lithium-sulfur batteries until now has been that they don’t last as long, being useable for about 100 charging cycles. Game supply and game card sleeve and trading card sleeve and soft card holder
Purdue researchers, funded by the Naval Enterprise Partnership teaming with Universities for National Excellence for Power, and Energy Research at Purdue, have found a way to increase the lifespan through a process that has the added bonus of being a convenient way to recycle plastic. Putting sulfur-soaked plastic in a microwave transforms the material into the ideal substance for increasing the life span of the batteries to more than 200 charging-discharging cycles, according to a paper that was recently published in ACS Applied Materials and Interfaces.
“No matter how many times you recycle plastic, that plastic stays on Earth,” said Vilas Pol, associate professor in Purdue’s School of Chemical Engineering. “We’ve been thinking of ways to get rid of it for a long time, and this is a way to at least add value. Game supply and game card sleeve and trading card sleeve and soft card holder
“Because lithium-sulfur batteries are getting more popular, we want to get a longer life sucked out of them,” Pol added. Game supply and game card sleeve and trading card sleeve and soft card holder
Low-density polyethylene (LDPE) helps address a long-standing issue with lithium-sulfur batteries—a phenomenon called the polysulfide shuttling effect that limits how long a battery can last between charges. When a current is applied to lithium-sulfur batteries, lithium ions migrate to the sulfur and a chemical reaction takes place to produce lithium sulfide. The byproduct of this reaction, polysulfide, tends to cross back over to the lithium side, preventing the migration of lithium ions to sulfur. This decreases the charge capacity of a battery as well as its life span.
“The easiest way to block polysulfide is to place a physical barrier between lithium and sulfur,” said Patrick Kim, a Purdue postdoc research associate in chemical engineering. Game supply and game card sleeve and trading card sleeve and soft card holder
Previous studies had attempted making this barrier out of biomass, such as banana peels and pistachio shells, because the pores in biomass-derived carbon had the potential to catch polysulfide, noted Purdue. “Every material has its own benefit, but biomass is good to keep and can be used for other purposes,” Pol said. Game supply and game card sleeve and trading card sleeve and soft card holder
Instead, researchers thought of how plastics might be incorporated into a carbon scaffold to suppress polysulfide shuttling in a battery. Past research had shown that LDPE yields carbon when combined with sulfonated groups.
Researchers soaked a plastic bag in a solvent containing sulfur and put it in a microwave to cheaply provide the quick boost in temperature needed for transformation into low-density polyethylene. The heat promoted the sulfonation and carbonization of the plastic and induced a higher density of pores for catching polysulfide. The LDPE plastic could then be made into a carbon scaffold to divide the lithium and sulfur halves of a better coin cell. Game supply and game card sleeve and trading card sleeve and soft card holder
“The plastic-derived carbon from this process includes a sulfonate group with a negative charge, which is also what polysulfide has,” Kim said. Sulfonated LDPE made into a carbon scaffold, therefore, suppressed polysulfide by having a similar chemical structure. Game supply and game card sleeve and trading card sleeve and soft card holder
“This is the first step for improving the capacity retention of the battery,” Pol said. “The next step is fabricating a bigger-sized battery utilizing this concept.” Game supply and game card sleeve and trading card sleeve and soft card holder