Local weather change is a significant world concern of the current century. It’s crucial to cut back carbon emissions by using renewable vitality sources and creating environment friendly vitality storage techniques. Lithium-ion batteries have excessive vitality density and an extended cycle life, making them indispensable in transportable electronics in addition to electrical autos. Nevertheless, the excessive price and restricted provide of lithium necessitate the event of different vitality storage techniques. To this finish, researchers have advised sodium-ion batteries (SIBs) as a potential candidate.
Moreover having physicochemical properties just like that of lithium, sodium is each sustainable and cost-effective. Nevertheless, its ions are massive with sluggish diffusion kinetics, hindering their lodging throughout the carbon microstructures of the commercialized graphite anodes. Consequently, SIB anodes undergo from structural instability and poor storage efficiency. On this regard, carbonaceous supplies doped with heteroatoms are exhibiting promise. Nevertheless, their preparation is difficult, costly, and time-consuming.
Just lately, a workforce of researchers, led by Professor Seung Geol Lee from Pusan Nationwide College in Korea, used quinacridones as precursors to arrange carbonaceous SIB anodes. “Natural pigments comparable to quinacridones have quite a lot of buildings and useful teams. In consequence, they develop completely different thermal decomposition behaviors and microstructures. When used as a precursor for vitality storage supplies, pyrolyzed quinacridones can drastically range the efficiency of secondary batteries. Due to this fact, it’s potential to implement a extremely environment friendly battery by controlling the construction of natural pigments precursor,” explains Prof. Lee. Their examine was made accessible on-line on 17 October 2022 and can be revealed in Quantity 453, Half 1 of the Chemical Engineering Journal on 1 February 2023.
The researchers targeted on 2,9-dimethylquinacridone (2,9-DMQA) of their examine. 2,9-DMQA has a parallel molecular packing configuration. Upon pyrolysis (thermal decomposition) at 600°C, 2,9-DMQA turned from reddish to black with a excessive char yield of 61%. The researchers subsequent carried out a complete experimental evaluation to explain the underlying pyrolysis mechanism.
They proposed that the decomposition of methyl substituents generates free radicals at 450°C, which kind polycyclic fragrant hydrocarbons with a longitudinally grown microstructure ensuing from bond bridging alongside the parallel packing course. Additional, nitrogen- and oxygen-containing useful teams in 2,9-DMQA launched gases, creating disordered domains within the microstructure. In distinction, pyrolyzed unsubstituted quinacridone developed extremely aggregated buildings. This advised that the morphological improvement was considerably affected by the crystal orientation of the precursor.
As well as, 2,9-DMQA pyrolyzed at 600°C exhibited a excessive charge functionality (290 mAh/g at 0.05 A/g ) and glorious cycle stability (134 mAh/g at 5 A/g for 1000 cycles) as an SIB anode. The nitrogen- and oxygen-containing teams additional enhanced battery storage by way of floor confinement and interlayer distance increment.
“Natural pigments comparable to quinacridones can be utilized as anode supplies in sodium-ion batteries. Given the excessive effectivity, they’ll present an efficient technique for mass manufacturing of large-scale vitality storage techniques,” concludes Prof. Lee.