The Kinetics and Product Characteristics of Oxygen Reduction and Evolution in LiO2 Batteries

摘要: Understanding the origin of substantial performance challenges limiting practical development Li–O2 batteries, such as low rate capability, limited cycle life (<100 cycles), and large voltage polarization (0.6–1 V) on charge, requires improved understanding chemical, electrochemical, morphological, electronic processes occurring in electrode. This chapter highlights current how kinetics reaction product characteristics batteries during discharge charge influence at cell level. First, a brief overview energy power various electrodes reported literature to date is presented for range O2 electrode materials designs benchmark what has been achieved laboratory scale. Next, we review chemical morphological oxygen reduction (discharge) process, with particular focus nanostructured carbon 1,2-dimethoxyethane (DME) electrolyte. The morphology shape evolution Li2O2 are discussed, including recent insights into microscale structure proposed growth mechanisms “toroidal” crystalline currents or overpotentials. We next discuss surface chemistry discharged electrodes, morphology-dependent Li2O2, reactivity between electrode, ether-based electrolytes, resulting parasitic products that form upon subsequent cycling. In light instabilities present nearly universally liquid cells, highlight work utilizing situ ambient pressure XPS (APXPS) examine electrochemistry battery operation an all-solid-state cell. Finally, charging carbon-nanostructured where found significantly overpotential required oxidation. Combined increasingly important researchers seek develop increased round-trip efficiency chemical/electrochemical reversibility approaching needed devices.