Using recycled tetrapak and Ag/BaMoO4 nanoparticles to make efficient and flexible solid state supercapacitors

Recycling materials containing plastics is of environmental interests because they are finally released in the oceans and rivers, producing contamination by microplastics suspended in the water. To palliate this problem, we fabricated supercapacitors (SCs) using recycled tetrapak/graphene as flexible electrode and the Ag/BaMoO4 (BAMO) NPs as the redox material. Those NPs had a rhombohedral morphology, average size of 655 nm and tetragonal structure according to the analysis by SEM and XRD. Solid state SCs were constructed using these electrodes and obtained a maximum capacitance and energy density values of 233 F g-1 and 88 Wh kg (1), respectively. When these SCs are made with BAMO NPs on their electrodes, the capacitance and energy density are increased up to 443 F g-1 and 173 Wh kg(1), respectively. The capacitance retention was calculated for the SC made with and without BAMO NPs after 500 cycles of charge/discharge, and obtained values of 92% and 83%, respectively. The higher capacitance retention obtained in the SCs made with BAMO NPs indicates that such nanomaterial improves their electrochemical stability. Surprisingly, the SCs made with BAMO NPs presented a stable output voltage of 0.93 V after 8 h of continuous discharge, which has not been previously observed in SCs made with recycled materials. Moreover, the absorbance, Raman and XPS measurements confirmed the presence of oxygen vacancies and species such as Ba2+/Ba+, Mo6+/Mo5+ and Aga(2+)/Ag+/Ag-0 in the tetrapak/graphene electrodes containing BAMO, which acted as redox centers for the charge storage. Hence, this research demonstrated that efficient SCs can be fabricated utilizing recycled tetrapack. Using this waste material could be useful to decrease the cost of the current supercapacitors and would reduce the contamination by plastics in the environment (the tretapak contains 24% of plastic).

Automated summary

Recycling materials containing plastics is important for environmental protection, as they can contribute to microplastic contamination in oceans and rivers. By using recycled tetrapak/graphene and Ag/BaMoO4 nanoparticles, the researchers fabricated supercapacitors with improved capacitance, energy density, and stability. This study demonstrates that utilizing recycled materials like tetrapak can reduce costs and plastic pollution in the environment.