Waste Not, Want Not: researchers Power Supercapacitors with Eggshells, โฃHemp, and Cement
BOSTON, MA โค- In aโ push for lasting energyโ storage, scientists are increasingly turning to unexpected sourcesโฃ – and waste products โ- to โbuild the next generation of โขsupercapacitors.Recent breakthroughs demonstrate the potential โฃof materials like eggshells, hemp, โand even cement to createโค functional, and surprisingly โdurable, energy storage devices.
The quest for eco-pleasant alternatives to traditional supercapacitor components, often reliant on scarce or environmentallyโ damaging materials, is gaining momentum. These new approaches not onlyโค address sustainability concerns but also offer cost-effective solutions for energy storage.
Eggs-cellent Energy Storage
Researchers โคhave successfully constructed a fully egg-basedโฃ supercapacitor, utilizing every partโค ofโ the egg. A team developed electrodes from carbonizedโ eggshells, leveraging their calcium carbonateโ composition. Egg whites and yolks, mixed with โpotassiumโค hydroxide and dried, formed a gel electrolyte.โฃ โขCrucially, theโ team repurposed eggshell membranes as separators, โcapitalizing on their naturallyโข interlaced micrometer-sized fiber structure toโ facilitate ion transport.
The resulting supercapacitor โฃproved flexible, maintaining capacitance even โwhen bent or twisted. Whileโ retaining 80 โคpercentโ of its original capacitance after 5,000 cycles, the performance is comparable to other supercapacitors built from naturalโข materials.
Hemp-Derived Supercapacitors Rival โขCommercial Standards
In Tรผrkiye, scientistsโค at Ondokuz Mayฤฑs University are harnessing โฃthe powerโ of pomegranate hemp plants.โข In 2024, they utilized the stems of โthese plants to produce activated carbon for a supercapacitor electrode.The process โinvolved drying,grinding,and chemicallyโฃ activating the hemp โขstems with sulfuricโค acid โand โฃpotassium hydroxide. โ
The resulting supercapacitor demonstrated remarkable stability,retaining 98 โpercent of its โฃoriginal capacitance after 2,000 cycles – a โคperformance level on par with supercapacitors made from conventional,non-biological materials. Theโ hemp-derived carbon โalso boasted an energy density โofโ 65 watt-hours per kilogram, aligningโข with commercial standards.
Cement: โA Surprisingly โEffective Electrode Material
Cement, a cornerstone of the construction industry, isโฃ alsoโฃ showing promise in the energyโฃ sector. โขA 2023 study from MIT researchers detailed the creation โฃof electrodes using water,โข nearly pure carbon, and โcement. The team theorizes a “synergy” between the hydrophilic cementโ and hydrophobic carbon enhancesโ the electrodes’ ability to โคhold ions during charging.
Testing eight electrode variations, the researchersโฃ found the โcement supercapacitors maintained capacitance with minimal loss evenโ after 10,000 cycles. Calculations suggest a single supercapacitor could theoretically store around 10 kilowattโ hoursโ – enough to power roughly one-third of an average American’s daily energy needs.
