Realizing an energy-dense, highly rechargeable nonaqueous lithium-oxygen battery in ambient air remains a big challenge because the active materials of the typical high-capacity cathode (Li 2 O 2 ) and anode (Li metal) are unstable in air. Herein, a novel lithium-oxygen full cell coupling a lithium anode protected by a composite layer of polyethylene oxide (PEO)/lithium aluminum titanium phosphate (LATP)/wax to a LiOH-based cathode is constructed. The protected lithium is stable in air and water, and permits reversible, dendrite-free lithium stripping/plating in a wet nonaqueous electrolyte under ambient air. The LiOH-based full cell reaction is immune to moisture (up to 99% humidity) in air and exhibits a much better resistance to CO 2 contamination than Li 2 O 2 , resulting in a more consistent electrochemistry in the long term. The current approach of coupling a protected lithium anode with a LiOH-based cathode holds promise for developing a long-life, high-energy lithium-air battery capable of operating in the ambient atmosphere.

Vagal afferents mediate sensitivity to low-threshold distension and 5-HT during postoperative ileus but not to high-threshold distension and bradykinin. Vagal inhibition of the intestinal immune response is present at 9 h but not detectable earlier, i.e., at 3 h of postoperative ileus when spinal reflex inhibition may prevail.

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Investigation of LiOH decomposition in nonaqueous electrolytes not only expands the fundamental understanding of four-electron oxygen evolution reactions in aprotic media but also is crucial to the development of high-performance lithium−air batteries involving the formation/decomposition of LiOH. In this work, we have shown that the decomposition of LiOH by ruthenium metal catalysts in a wet DMSO electrolyte occurs at the catalyst−electrolyte interface, initiated via a potential-triggered dissolution/reprecipitation process. The in situ UV−vis methodology devised herein provides direct experimental evidence that the hydroxyl radical is a common reaction intermediate formed in several nonaqueous electrolytes; this method is applicable to study other battery systems. Our results highlight that the reactivity of the hydroxyl radical toward nonaqueous electrolyte represents a major factor limiting O 2 evolution during LiOH decomposition. Coupling catalysts restraining hydroxyl reactivity with electrolytes more resistant to hydroxyl radical attack could help improve the reversibility of this reaction.

By replacing the conventional graphite-based anode (372 mAh g −1 for LiC 6 , on the basis of mass of C) with silicon (3579 mAh g −1 for Li 15 Si 4 , on the basis of mass of Si) or lithium metal (3860 mAh g −1 ; based on the mass of Li) anodes, the practical energy density of LIB single cells can be increased to 300-400 Wh kg −1 . [4] Nevertheless, to surpass the commonly targeted goal of 500 Wh kg −1 , [5] alternative cathodic chemistries beyond Li-ion intercalation are required. Using O 2 as an active material for electrochemical energy storage is appealing in terms of cost and availability, and when coupled to Li metal, lithium-air batteries (LABs) could deliver energy densities up to 3505 Wh kg −1 (theoretical value). [1c,6] Several studies have demonstrated nonaqueous Li-O 2 batteries with energy densities of up to 1230 Wh kg −1 using novel cell designs, [7] although the cycle life needs to be improved. Table S1, Supporting Information, summarizes the high-energy lithium-air full cells reported to date.The theoretical energy density of nonaqueous LABs depends on the specific cathodic half-cell reaction (Equations ( 1)-( 4), note that all voltages are referred to against Li/Li + ), and thus the chemical composition of the discharge product. [8] Thus far, successfully tested discharge products for aprotic LABs include LiO 2 , Li 2 O 2 , Li 2 O, and LiOH. Both Li 2 O 2 and Li 2 O are thermodynamically stable compounds (Equations ( 1) and ( 2)), whereas LiO 2 is unstable at standard conditions but has been reported to form in LABs assisted by Ir-and Pd-catalytic systems (Equation ( 3)). [8a-d] Formation of Li 2 O during discharge involves rupture of the OO bond and is thus less kinetically favorable than Li 2 O 2 formation, unless discharge occurs in the presence of a catalyst such as nickel at above 150 °C. 2 2 1 8b,9 (4) Notably, one issue that LiO 2 , Li 2 O 2 , and Li 2 O have in common is their moisture and carbon dioxide sensitivity, as The realization of practical nonaqueous lithium-air batteries (LABs) calls for novel strategies to address their numerous theoretical and technical challenges. LiOH formation/decomposition has recently been proposed as a promising alternative route to cycling LABs via Li 2 O 2 . Herein, the progress in developing LiOH-based nonaqueous LABs is reviewed. Various catalytic systems, either soluble or solid-state, that can activate a LiOH-based electrochemistry are compared in detail, with emphasis in providing an updated understanding of the oxygen reduction and evolution reactions in nonaqueous media. We identify the key factors that can switch the cell chemistry between Li 2 O 2 and LiOH and highlight the debate around these routes, as well as rationalize potential causes for these opposing opinions. The identities of the reaction intermediates, activity of redox mediators and additives, location of reaction interfaces, causes of parasitic reactions, as well as the effect of CO 2 on the LiOH electrochemistry, all play a critical role in altering the relative rates of ...