Crystal Phase-Controlled Modulation of Binary Transition Metal Oxides for Highly Reversible Li–O₂ Batteries

Abstract

Reducing charge−discharge overpotential of transition metal oxide catalysts can eventually enhance the cell efficiency and cycle life of Li−O 2 batteries. Here, we propose that crystal phase engineering of transition metal oxides could be an effective way to achieve the above purpose. We establish controllable crystal phase modulation of the binary Mn x Co 1−x O by adopting a cation regulation strategy. Systematic studies reveal an unprecedented relevancy between charge overpotential and crystal phase of Mn x Co 1−x O catalysts, whereas a dramatically reduced charge overpotential (0.48 V) via a rational optimization of Mn/Co molar ratio = 8/2 is achieved. Further computational studies indicate that the different morphologies of Li 2 O 2 should be related to different electronic conductivity and binding of Li 2 O 2 on crystal facets of Mn x Co 1−x O catalysts, finally leading to different charge overpotential. We anticipate that this specific crystal phase engineering would offer good technical support for developing highperformance transition metal oxide catalysts for advanced Li−O 2 batteries.

Ether-based electrolytes for sodium ion batteries

“…62,63 Li-O 2 batteries, which possess the highest theoretical energy density among the possible secondary battery technologies with the formation of the discharge product lithium peroxide (Li 2 O 2 ), have received much attention. [64][65][66] However, Li-O 2 batteries face the severe challenges of sluggish reaction kinetics of the O 2 electrode and the parasitic reaction between intermediates/products and cell components, which inevitably result in a poor cycle life, low rate capability and inferior Coulombic efficiency. 67,68 The performance of the Li-O 2 battery is strongly related to its electrolyte.…”

Recent advances in heterostructured cathodic electrocatalysts for non-aqueous Li–O2batteries

“…However, most of these non-precious catalysts only show single catalytic activity for the OER or ORR, and the development of high-efficiency bifunctional catalysts is actually challenging and essential for the practical application of Li–O 2 batteries. 53–55 At present, various strategies including surface modification, 56–58 strain engineering, 59,60 phase modulation 61–63 and heterostructure construction have been explored to realize the bifunctional ability for Li–O 2 catalysis. 64–66…”

Accelerating the reaction kinetics of lithium–oxygen chemistry by modulating electron acceptance–donation interaction in electrocatalysts

“…5,6 Nevertheless, the practical applications of LOBs are greatly hampered by the large voltage hysteresis and poor cyclability caused by the sluggish deposition (oxygen reduction reaction, ORR) and decomposition (oxygen evolution reaction, OER) kinetics of Li 2 O 2 . 7,8 In response, tremendous efforts have been devoted to developing advanced electrocatalysts to accelerate the ORR/OER kinetics, including noble metals, 9,10 metal oxides, 11,12 suldes 13,14 and nitrides. 15,16 Unfortunately, the above inorganic components are inevitably subjected to the attack of the highly reactive oxygen species, resulting in the aggravation and degradation of the electrode materials and thus poor stability of LOBs.…”

“…In response, tremendous efforts have been devoted to developing advanced electrocatalysts to accelerate the ORR/OER kinetics, including noble metals, 9,10 metal oxides, 11,12 sulfides 13,14 and nitrides. 15,16 Unfortunately, the above inorganic components are inevitably subjected to the attack of the highly reactive oxygen species, resulting in the aggravation and degradation of the electrode materials and thus poor stability of LOBs.…”