Upcycling Linear Low-Density Polyethylene Waste into Graphene for High Mass Loading Supercapacitors

Conference · Wed Oct 09 04:00:00 EDT 2024

DOI:https://doi.org/10.2172/2460430· OSTI ID:2460430

Gao, Yuan ^[1]; Pham, Viet Hung ^[1]; Huynh, Ngoc Tien ^[1]; Wang, Congjun ^[2]; Kim, Ki-Joong ^[2]; Matranga, Christopher ^[2]

---

1. NETL Site Support Contractor, National Energy Technology Laboratory
2. NETL

Polyethylene is notoriously difficult to upcycle because it decomposes into light gases at approximately 350-400 °C which prevents processing it at higher temperatures to convert it into electrode materials. We address this challenge by using an air-based, thermos-oxidative process, which heats linear low-density polyethylene (LLDPE) just below the decomposition point to initiate oxidation and cross-linking of LLDPE alkyl chains. These molecular transformations allow LLDPE to be graphenized at 950 °C without decomposing. The LLDPE-derived graphene (LLDPE-G) has a BET specific surface area up to 1,800 m2/g and Raman ID/IG ratio of 0.85. When used as electrode material for a symmetric supercapacitor with the 1 M H2SO4 electrolyte, LLDPE-G possesses an specific capacitance up to 175 F/g at mass loading of 20 mg/cm2, yielding an areal capacitance of 3.5 F/cm2. The cycling stability with capacitance demonstrates a retention of 95.8% after 100,000 cycles at high current density of 4.0 A/g.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy and Carbon Management (FECM); USDOE Office of Fossil Energy and Carbon Management (FECM), Office of Resource Sustainability (FE-30)
• OSTI ID: 2460430
• Country of Publication: United States
• Language: English