Bringing Real-World Energy-Storage Research into a Second-Year Physical-Chemistry Lab Using a MnO2-Based Supercapacitor

摘要

As the need for alternative energy becomes increasingly important, energy research and related industries are rapidly expanding. This lab incorporates current energy-storage research into a second-year lab that instills real-world, industry-relevant knowledge and skills while teaching and reinforcing physical-chemistry concepts. A manganese oxide electrode, aqueous-Na2SO4-electrolyte super capacitor system is used because it has no air or water sensitivity, unlike most battery technologies, so it is easy to implement in an undergraduate-lab setting. Manganese oxide is an increasingly popular supercapacitor material, and this lab introduces the concept of pseudocapacitance, in which current flows while still being governed by the Nernst equation (i.e., at equilibrium). Students conduct realistic and industrially relevant electrochemical experiments; they electro-deposit manganese oxide films and test them using cyclic voltammetry. Students compare the manganese oxide results to those from a nonpseudocapacitive system (i.e., a poor supercapacitor). In doing so, they learn the concepts of charge storage and energy and power (and their important differences), while reinforcing the physical-chemistry topics of thermodynamics and kinetics, all within a frame of familiar electrochemical knowledge (i.e., the Nernst equation). This lab can be completed in one 4 h laboratory period or in a 3 h period if the solutions are provided to the students or they prepare them a week in advance. Student interest and engagement is heightened by their being able to see the real-world applications and skills.