A Potential Electrolyte for Energy Conversion Device using Waste Eggshells and Banana Peel

Abstract

The demand of potential energy storage and energy conversion devices has alarmed our country. Global warming is also destroying the echo system and environment due to enhancement of greenhouse gasses in the atmosphere. The key to success for an organization is to produce clean, sustainable and affordable energy which may leads to the healthy impact on the humanity and atmosphere by reduction of pollution and utilizing renewable resources of energy. Energy by renewable means it would have an interesting solution to this problem. Pakistan is among-st the top 10 leading egg production countries producing 18 billion eggs annually. These waste materials are abundantly available worldwide and Asia is at top in production of bananas too. Egg shells contain calcium carbonate (CaCO3) which makes up 95 % of its constituents. Eggshells are rich source of raw calcium (39% elemental calcium). That will be used to obtain calcium acetate Ca(CH3COO)2 and calcium oxide CaO. Similarly banana peel is a source to get potassium. Dried banana peel comprise of 42% potassium. Burning of potassium would convert it into potassium carbonate. Calcium acetate Ca(CH3COO)2 and calcium oxide CaO will further be used as dopants to form calcium doped ceria electrolyte. 4 samples were prepared by using the method of co-precipitation named CDC-1, CDC-2, K2CO3@CDC-1, K2CO3@CDC2. upon sample 3 and sample coating of extracted potassium carbonate was done. Provided is the SOFC calcium doped ceria electrolyte upon with coating of potassium carbonate is done to enhance its functionality, durability, stability and to make it duel ion conductor. Coating of potassium carbonate on calcium doped ceria (CDC) will provide the interface/ core shell structures which play a vital role in lowering the working temperature of SOFC by making it dual ion conductor. XRD and FTIR analysis was done to analyse crystal orientation/crystal structure, crystallite size, and existence of chemical bonds in synthesized samples. DC conductivity using 4 point probe technique was done to analyse conductivity of prepared samples. Power density and current density was calculated by fuel cell performance graphs. The electrochemical performance values are comparable with the literature values where same material was used using chemical from labs. It gives the idea about of quality of extracted materials with proper doping as it was further evident from characterization tools like XRD and FTIR. Sample 3 and sample 4 made by coating of potassium carbonate upon prepared ceria samples provided much encouraging and excellent results in the same temperature xi range making the conductivity value approximately 6.4 and 6.45 S/cm.K with activation energies of 0.20 eV in the temperature range of 450 to 750ºC. An analysis was also made comparing between particle size and conductivity. Smallest crystallite size calculated using scherrer formula was of K2CO3@CDC-2 which was calculated 41.31 nm which provides maximum output value for conductivity, OCV, power density and current density.