Martin Z. Bazant, visiting professor, Materials Science & Engineering, SUNCAT Center, Stanford University
Next generation batteries must achieve significant reductions in cost (for stationary energy storage) or weight (for electrified transportation). In this effort, the chemistry of new battery materials has received the most attention, but the physics of convection, electromigration, and phase transformations are also critical to understand and exploit for engineering design. For example, flow batteries decouple energy (in tanks) and power (in the stack) and exploit convection to cycle ultra-low-cost reactants, such as zinc-iron and hydrogen-bromine, at high rates, even without expensive membranes. In principle, high energy density can be achieved in the same way in lithium-bromine-oxygen flow batteries. Phase transformations must also be controlled, in Li-ion and Li-metal batteries. In particular, most future battery concepts for transportation assume a rechargeable lithium metal anode, which must overcome morphological instabilities to achieve stable cycling (free of dendrites and without excessive SEI growth). Some progress on all of these problems will be presented.