Learning New Things from Old Chemistries: Revisiting Ideas Before Lithium Ion
Dan Steingart, Assistant Professor, Princeton University, Department of Mechanical and Aerospace Engineering, Andlinger Center for Energy and the Environment
Friday, February 5, 2016
Endeavors in electrochemical energy storage are industrial masochism for the same reason they are academic hedonism: a working, rechargeable battery represents a tight coupling of multiphase phenomena across chemical, electrical, thermal and mechanical domains. Despite these couplings, most treatments of batteries in the academic literature emphasize the material challenges and opportunities as opposed to the system level workings. There are at least three good reasons for this: 1) to date, tools for examining the structure of “real” cells in operando are largely limited to synchrotron x-ray and neutron methods, 2) full cells are products engineered for application demands and not platonic ideals and 3) material improvements can have enormous impact on battery performance.
Yet understanding and examining the physical dynamics of cells in a “scaled context” is still a worthwhile academic endeavor. The battery as a system presents problems that are difficult to decouple, but the study of such problems can introduce new opportunities and inform electrochemical reactor designs and material utilization strategies.
By studying full “scaled” cell behaviors we have learned how to compensate for certain material disadvantages and to create batteries and components that can meet performance targets which challenge traditional materials-first strategies. First, I will show that the “dendrite” may not be the universal anathema it is made out to be (at least in a water stable system). Second, I will show what we can learn from the many reasons it is difficult to cycle a traditional “bobbin” AA cell. Finally, I will examine a “stupid battery trick” unique to the zinc alkaline bobbin that can teach us something (perhaps) universally applicable to all closed batteries.