My primary research interests are in the fields of solid state chemistry and electrochemistry; particularly solid state ionics, which embraces ionically conducting solids and intercalation compounds. I am interested in the fundamental science of ionically conducting solids (ceramic and polymeric materials) and intercalation compounds, in the synthesis of new materials with new properties or combinations of properties, in understanding these properties and in exploring their applications in new devices, especially energy storage devices such as rechargeable lithium batteries. Although ionically conducting solids represent the starting point for much of our research, we have extended our interests well beyond the confines of this subject alone.
Lithium-Oxygen Batteries and Related Systems: Potential, Status, and Future.
The goal of limiting global warming to 1.5 °C requires a drastic reduction in CO2 emissions across many sectors of the world economy. Batteries are vital to this endeavor, whether used in electric vehicles, to store renewable electricity, or in aviation. Present lithium-ion technologies are preparing the public for this inevitable change, but their maximum theoretical specific capacity presents a limitation. Their high cost is another concern for commercial viability. Metal-air batteries have the highest theoretical energy density of all possible secondary battery technologies and could yield step changes in energy storage, if their practical difficulties could be overcome. The scope of this review is to provide an objective, comprehensive, and authoritative assessment of the intensive work invested in nonaqueous rechargeable metal-air batteries over the past few years, which identified the key problems and guides directions to solve them. We focus primarily on the challenges and outlook for Li-O2 cells but include Na-O2, K-O2, and Mg-O2 cells for comparison. Our review highlights the interdisciplinary nature of this field that involves a combination of materials chemistry, electrochemistry, computation, microscopy, spectroscopy, and surface science. The mechanisms of O2 reduction and evolution are considered in the light of recent findings, along with developments in positive and negative electrodes, electrolytes, electrocatalysis on surfaces and in solution, and the degradative effect of singlet oxygen, which is typically formed in Li-O2 cells.
First cycle voltage hysteresis in Li-rich 3d cathodes associated with molecular O2 trapped in the bulk