Metal-Organic Framework with Dual Excitation Pathways as Efficient Bifunctional Catalyst for Photo-assisted Li-O2 Batteries.

Li-O2 batteries (LOBs) have sparked significant interest due to their fascinating high theoretical energy density. However, the large overpotential for the formation and oxidation of Li2O2 during charge and discharge process seriously hinders the further development and application of LOBs. In this work, metal-organic frameworks (MOFs) with different metal clusters (Fe, Ti, Zr) are successfully synthesized, and they are employed as the photoelectrodes for the photo-assisted LOBs. The special dual excitation pathways of Fe-MOF under illumination and the superior separation efficiency of photocarriers, which significantly enhance the activation of O2/Li2O2, improving the catalytic activity of oxygen reduction reaction and oxygen evolution reaction. Moreover, compared to traditional inorganic semiconductor crystals, Fe-MOF exhibits large specific surface area and excellent O2 adsorption ability. Therefore, the LOB with Fe-MOF as the cathode exhibits large specific capacity, ultralow charge/discharge overpotential of 0.22 V at 0.05 mA cm-2 and excellent stability of 195 cycles under illumination. This study provides an environmentally friendly and highly efficient photocatalyst for LOBs, and a new strategy for designing photoelectrodes.

Unlocking the critical roles of N, P Co-Doping in MXene for Lithium-Oxygen Batteries: Elevated d-Band center and expanded interlayer spacing.

The design and fabrication of bifunctional catalysts with high electrocatalytic activity and stability are critical for developing highly reversible Li-O2 batteries (LOBs). Herein, the N, P co-doped MXene (NP-MXene) is prepared by one-step annealing method and evaluated as bifunctional catalyst for LOBs. The results suggest that the P doping plays a crucial role in increasing interlayer distance of MXene, thereby effectively providing more active sites, fast mass transfer, and ample space for the deposition/decomposition of Li2O2. Moreover, the N doping can significantly elevate the d-band center of Ti, thereby remarkably improving the adsorption of reaction intermediates and accelerating the deposition/decomposition of Li2O2 films. Consequently, the MXene-based LOBs deliver an ultrahigh specific capacity of 13,995 mAh/g at 500 mA g-1, a discharge/charge voltage gap of 0.89 V, and a cycle life up to 523 cycles with a limited capacity of 1000 mAh/g at 500 mA g-1. Impressively, the as-fabricated flexible LOBs with NP-MXene cathode display excellent cycling stability and ability to continuously power LEDs even after bending. Our findings pave the road of heteroatom doped MXenes as next-generation electrodes for high-performance energy storage and conversion systems.

Exciton Dissociation into Charge Carriers in Porphyrinic Metal-Organic Frameworks for Light-Assisted Li-O2 Batteries.

Light-assisted Li-O2 batteries exhibit a high round-trip efficiency attributable to the assistance of light-generated electrons and holes in oxygen reduction and evolution reactions. Nonetheless, the excitonic effect arising from Coulomb interaction between electrons and holes impedes carrier separation, thus hindering efficient utilization of photo-energy. Herein, porphyrinic metal-organic frameworks with (Fe2Ni)O(COO)6 clusters are used as photocathodes to accelerate exciton dissociation into charge carriers for light-assisted Li-O2 batteries. The coupling of Ni 3d and Fe 3d orbitals boosts ligand-to-metal cluster charge transfer, and hence drives exciton dissociation and activates O2 for superoxide (•O2 -) radicals, rather than singlet oxygen (1O2) under photoexcitation. These enable the light-assisted Li-O2 batteries with a low total overvoltage of 0.28 V and round-trip efficiency of 92% under light irradiation of 100 mW cm-2. This work highlights the excitonic effect in photoelectrochemical processes and provides insights into photocathode design for light-assisted Li-O2 batteries.

Modulating the d-Band Center of RuO2 via Ni Incorporation for Efficient and Durable Li-O2 batteries.

Rechargeable Li-O2 batteries (LOBs) are considered as one of the most promising candidates for new-generation energy storage devices. One of major impediments is the poor cycle stability derived from the sluggish reaction kinetics of unreliable cathode catalysts, hindering the commercial application of LOBs. Therefore, the rational design of efficient and durable catalysts is critical for LOBs. Optimizing surface electron structure via the negative shift of the d-band center offers a reasonable descriptor for enhancing the electrocatalytic activity. In this study, the construction of Ni-incorporating RuO2 porous nanospheres is proposed as the cathode catalyst to demonstrate the hypothesis. Density functional theory calculations reveal that the introduction of Ni atoms can effectively modulate the surface electron structure of RuO2 and the adsorption capacities of oxygen-containing intermediates, accelerating charge transfer between them and optimizing the growth pathway of discharge products. Resultantly, the LOBs exhibit a large discharge specific capacity of 19658 mA h g-1 at 200 mA g-1 and extraordinary cycle life of 791 cycles. This study confers the concept of d-band center modulation for efficient and durable cathode catalysts of LOBs.

Atomic-Scale Cryo-TEM Studies of the Electrochemistry of Redox Mediator in Li-O2 Batteries.

Rechargeable aprotic lithium (Li)-oxygen battery (LOB) is a potential next-generation energy storage technology because of its high theoretical specific energy. However, the role of redox mediator on the oxide electrochemistry remains unclear. This is partly due to the intrinsic complexity of the battery chemistry and the lack of in-depth studies of oxygen electrodes at the atomic level by reliable techniques. Herein, cryo-transmission electron microscopy (cryo-TEM) is used to study how the redox mediator LiI affects the oxygen electrochemistry in LOBs. It is revealed that with or without LiI in the electrolyte, the discharge products are plate-like LiOH or toroidal Li2O2, respectively. The I2 assists the decomposition of LiOH via the formation of LiIO3 in the charge process. In addition, a LiI protective layer is formed on the Li anode surface by the shuttle of I3 -, which inhibits the parasitic Li/electrolyte reaction and improves the cycle performance of the LOBs. The LOBs returned to 2e- oxygen reduction reaction (ORR) to produce Li2O2 after the LiI in the electrolyte is consumed. This work provides new insight on the role of redox mediator on the complex electrochemistry in LOBs which may aid the design LOBs for practical applications.

Dynamic Modulation of Li2O2 Growth in Li-O2 Batteries through Regulating Oxygen Reduction Kinetics with Photo-Assisted Cathodes.

Widely acknowledged that the capacity of Li-O2 batteries (LOBs) should be strongly determined by growth behaviors of the discharge product of lithium peroxide (Li2O2) that follows both coexisting surface and solution pathways. However until now, it remains still challenging to achieve dynamic modulation on Li2O2 morphologies. Herein, the photo-responsive Au nanoparticles (NPs) supported on reduced oxide graphene (Au/rGO) have been utilized as cathode to manipulate oxygen reduction reaction (ORR) kinetics by aid of surface plasmon resonance (SPR) effects. Thus, we can experimentally reveal the importance of matching ORR kinetics with Li+ migration towards battery performance. Moreover, it is found that Li+ concentration polarization caused "sudden death" of LOBs is supposed to be just a form of suspended animation that could timely recover under irradiation. This work provides us an in-depth explanation on the working mechanism of LOBs from a kinetic perspective, offering valuable insights for the future battery design.

Highly Stable Organic Molecular Porous Solid Electrolyte with One-Dimensional Ion Migration Channel for Solid-State Lithium-Oxygen Battery.

Solid-state lithium-oxygen (Li-O2) batteries have been widely recognized as one of the candidates for the next-generation of energy storage batteries. However, the development of solid-state Li-O2 batteries has been hindered by the lack of solid-state electrolyte (SSE) with high ionic conductivity at room temperature, high Li+ transference number, and the high stability to air. Herein, the organic molecular porous solid cucurbit[7]uril (CB[7]) with one-dimensional (1D) ion migration channels is developed as the SSE for solid-state Li-O2 batteries. Taking advantage of the 1D ion migration channel for Li+ conduction, CB[7] SSE achieves high ionic conductivity (2.45 × 10-4 S cm-1 at 25 °C). Moreover, the noncovalent interactions facilitated the immobilization of anions, realizing a high Li+ transference number (tLi + = 0.81) and Li+ uniform distribution. The CB[7] SSE also shows a wide electrochemical stability window of 0-4.65 V and high thermal stability and chemical stability, as well as realizes stable Li+ plating/stripping (more than 1000 h at 0.3 mA cm-2). As a result, the CB[7] SSE endows solid-state Li-O2 batteries with superior rate capability and long-term discharge/charge stability (up to 500 h). This design strategy of CB[7] SSE paves the way for stable and efficient solid-state Li-O2 batteries toward practical applications.

Coupling MoSe2 with Non-Stoichiometry Ni0.85 Se in Carbon Hollow Nanoflowers for Efficient Electrocatalytic Synergistic Effect on Li-O2 Batteries.

Li-O2 batteries could deliver ultra-high theoretical energy density compared to current Li-ion batteries counterpart. The slow cathode reaction kinetics in Li-O2 batteries, however, limits their electrocatalytic performance. To this end, MoSe2 and Ni0.85 Se nanoflakes were decorated in carbon hollow nanoflowers, which were served as the cathode catalysts for Li-O2 batteries. The hexagonal Ni0.85 Se and MoSe2 show good structural compatibility with the same space group, resulting in a stable heterogeneous structure. The synergistic interaction of the unsaturated atoms and the built-in electric fields on the heterogeneous structure exposes abundant catalytically active sites, accelerating ion and charge transport and imparting superior electrochemical activity, including high specific capacities and stable cycling performance. More importantly, the lattice distances of the Ni0.85 Se (101) plane and MoSe2 (100) plane at the heterogeneous interfaces are highly matched to that of Li2 O2 (100) plane, facilitating epitaxial growth of Li2 O2 , as well as the formation and decomposition of discharge products during the cycles. This strategy of employing nonstoichiometric compounds to build heterojunctions and improve Li-O2 battery performance is expected to be applied to other energy storage or conversion systems.

Binder-Free Cnt Cathodes for Li-O2 Batteries with More Than One Life.

Li-O2 batteries (LOB) performance degradation ultimately occurs through the accumulation of discharge products and irreversible clogging of the porous electrode during the cycling. Electrode binder degradation in the presence of reduced oxygen species can result in additional coating of the conductive surface, exacerbating capacity fading. Herein, a facile method to fabricate free-standing is established, binder-free electrodes for LOBs in which multi-wall carbon nanotubes form cross-linked networks exhibiting high porosity, conductivity, and flexibility. These electrodes demonstrate high reproducibility upon cycling in LOBs. After cell death, efficient and inexpensive methods to wash away the accumulated discharge products are demonstrated, as reconditioning method. The second life usage of these electrodes is validated, without noticeable loss of performance. These findings aim to assist in the development of greener high energy density batteries while reducing manufacturing and recycling costs.

Engineering dual-crystal configurations in perovskite oxides boosts electrocatalysis of lithium-oxygen batteries.

Sculpting crystal configurations can vastly affect the charge and orbital states of electrocatalysts, fundamentally determining the catalytic activity of lithium-oxygen (Li-O2) batteries. However, the crucial role of crystal configurations in determining the electronic states has usually been neglected and needs to be further examined. Herein, we introduce orthorhombic and trigonal system into 0.5La0.6Sr0.4MnO3-0.5LaMn0.6Co0.4O3 (LSMCO) by selectively incorporating Sr and Co cations into the LaMnO3 framework during the sol-gel process, which is used to explore the relationship among crystal structure, electronic states and catalytic performance. Based on both experimental and theoretical calculations, the dual-crystal configurations induce strong lattice distortion, which promotes MnO6 octahedra vibration and shortened MnO bonds. Furthermore, the suppressed Jahn-Teller distortion weakens the orbital arrangement and accelerates the charge delocalization, leading to the conversion of Mn3+ to Mn4+ and optimized electronic states. Ultimately, this resulted in optimized Mn 3d and O 2p orbital hybridization and activated lattice oxygen function, leading to a significant improvement in electrocatalytic activity. The LSMCO catalyzed Li-O2 battery achieves enhanced discharge capacity of 14498.7 mAh/g and cycling stability of 258 cycles. This work highlights the significance of inner structure and presents a feasible strategy for engineering crystal configurations to boost electrocatalysis of Li-O2 batteries.

Sabatier Relations in Electrocatalysts Based on High-entropy Alloys with Wide-distributed d-band Centers for Li-O2 Batteries.

Li-O2 battery (LOB) is a promising "beyond Li-ion" technology with ultrahigh theoretical energy density (3457 Wh kg-1 ), while currently impeded by the sluggish cathodic kinetics of the reversible gas-solid reaction between O2 and Li2 O2 . Despite many catalysts are developed for accelerating the conversion process, the lack of design guidance for achieving high performance makes catalysts exploring aleatory. The Sabatier principle is an acknowledged theory connecting the scaling relationship with heterogeneous catalytic activity, providing a tradeoff strategy for the topmost performance. Herein, a series of catalysts with wide-distributed d-band centers (i.e., wide range of adsorption strength) are elaborately constructed via high-entropy strategy, enabling an in-depth study of the Sabatier relations in electrocatalysts for LOBs. A volcano-type correlation of d-band center and catalytic activity emerges. Both theoretical and experimental results indicate that a moderate d-band center with appropriate adsorption strength propels the catalysts up to the top. As a demonstration of concept, the LOB using FeCoNiMnPtIr as catalyst provides an exceptional energy conversion efficiency of over 80 %, and works steadily for 2000 h with a high fixed specific capacity of 4000 mAh g-1 . This work certifies the applicability of Sabatier principle as a guidance for designing advanced heterogeneous catalysts assembled in LOBs.

Terephthalic Acid Intercalated CoNi-LDH Materials for Improved Li-O2 Battery.

CoNi-LDH (layered CoNi double hydroxides) hollow nanocages with specific morphology are obtained by Ni ion etching of ZIF-67 (Zeolitic imidazolate framework-67). The structure of the layered materials is further modified by molecular intercalation. The original interlayer anions are replaced by the ion exchange effect of terephthalic acid, which helps to increase the interlayer distance of the material. The intercalated cage-like structures not only benefit for the storage of oxygen, and the discharge product reaction, but also have more support between the material layers. The experimental results show that the excessive use of intercalation agent will affect structural stability of the intercalated CoNi-LDH. By adjusting the amount of terephthalic acid, the intercalated CoNi-LDH-2 (with 0.02 mmol terephthalic acid intercalated) is not easy to collapse after 209 cycles and shows the best electrochemical performance in Li-O2 battery.

Efficient Fe3C-CF Cathode Catalyst Based on the Formation/Decomposition of Li2-xO2 for Li-O2 Batteries.

Lithium-oxygen batteries have attracted considerable attention in the past several years due to their ultra-high theoretical energy density. However, there are still many serious issues that must be addressed before considering practical applications, including the sluggish oxygen redox kinetics, the limited capacity far from the theoretical value, and the poor cycle stability. This study proposes a surface modification strategy that can enhance the catalytic activity by loading Fe3C particles on carbon fibers, and the microstructure of Fe3C particle-modified carbon fibers is studied by multiple materials characterization methods. Experiments and density functional theory (DFT) calculations show that the discharge products on the Fe3C carbon fiber (Fe3C-CF) cathode are mainly Li2-xO2. Fe3C-CF exhibits high catalytic ability based on its promotion of the formation/decomposition processes of Li2-xO2. Consequently, the well-designed electrode catalyst exhibits a large specific capacity of 17,653.1 mAh g-1 and an excellent cyclability of 263 cycles at a current of 200 mA g-1.

Optimizing Eg Orbital Occupancy of Transition Metal Sulfides by Building Internal Electric Fields to Adjust the Adsorption of Oxygenated Intermediates for Li-O2 Batteries.

Li-O2 batteries are acknowledged as one of the most promising energy systems due to their high energy density approaching that of gasoline, but the poor battery efficiency and unstable cycling performance still hinder their practical application. In this work, hierarchical NiS2 -MoS2 heterostructured nanorods are designed and successfully synthesized, and it is found that heterostructure interfaces with internal electric fields between NiS2 and MoS2 optimized eg orbital occupancy, effectively adjusting the adsorption of oxygenated intermediates to accelerate reaction kinetics of oxygen evolution reaction and oxygen reduction reaction. Structure characterizations coupled with density functional theory calculations reveal that highly electronegative Mo atoms on NiS2 -MoS2 catalyst can capture more eg electrons from Ni atoms, and induce lower eg occupancy enabling moderate adsorption strength toward oxygenated intermediates. It is evident that hierarchical NiS2 -MoS2 nanostructure with fancy built-in electric fields significantly boosted formation and decomposition of Li2 O2 during cycling, which contributed to large specific capacities of 16528/16471 mAh g-1 with 99.65% coulombic efficiency and excellent cycling stability of 450 cycles at 1000 mA g-1 . This innovative heterostructure construction provides a reliable strategy to rationally design transition metal sulfides by optimizing eg orbital occupancy and modulating adsorption toward oxygenated intermediates for efficient rechargeable Li-O2 batteries.

MOF-Derived Mn2 O3 Nanocage with Oxygen Vacancies as Efficient Cathode Catalysts for Li-O2 Batteries.

Designing efficient and cost-effective electrocatalysts is the primary imperative for addressing the pivotal concerns confronting lithium-oxygen batteries (LOBs). The microstructure of the catalyst is one of the key factors that influence the catalytic performance. This study proceeds to the advantage of metal-organic frameworks (MOFs) derivatives by annealing manganese 1,2,3-triazolate (MET-2) at different temperatures to optimize Mn2 O3 crystals for special microstructures. It is found that at 350 °C annealing temperature, the derived Mn2 O3 nanocage maintains the structure of MOF, the inherited high porosity and large specific surface area provide more channels for Li+ and O2 diffusion, beside the oxygen vacancies on the surface of Mn2 O3 nanocages enhance the electrocatalytic activity. With the synergy of unique structure and rich oxygen vacancies, the Mn2 O3 nanocage exhibits ultrahigh discharge capacity (21 070.6 mAh g-1 at 500 mA g-1 ) and excellent cycling stability (180 cycles at the limited capacity of 600 mAh g-1 with a current of 500 mA g-1 ). This study demonstrates that the Mn2 O3 nanocage structure containing oxygen vacancies can significantly enhance catalytic performance for LOBs, which provide a simple method for structurally designed transition metal oxide electrocatalysts.

Freestanding MOF-Derived Honeycomb-Shape Porous MnOC@CC as an Electrocatalyst for Reversible LiOH Chemistry in Li-O2 Batteries.

In rechargeable Li-O2 batteries, the electrolyte and the electrode are prone to be attacked by aggressive intermediates (O2- and LiO2) and products (Li2O2), resulting in low energy efficiency. It has been reported that in the presence of water, the formation of low-activity LiOH is more stable for electrolyte and electrode, effectively reducing the production of parasitic products. However, the reversible formation and decomposition of LiOH catalyzed by solid catalysts is still a challenge. Here, a freestanding metal-organic framework (MOF)-derived honeycomb-shape porous MnOC@CC cathode was prepared for Li-O2 batteries by in situ growth of urchin-like Mn-MOFs on carbon cloth (CC) and carbonization. The battery with the MnOC@CC cathode exhibits an ultrahigh practical discharge specific capacity of 22,838 mAh g-1 at 200 mA g-1, high-rate capability, and more stable cycling, which is superior to the MnOC powder cathode. X-ray diffraction and Fourier transform infrared results identify that the discharge product of the batteries is LiOH rather than highly active Li2O2, and no parasitic products were found during operation. The MnOC@CC cathode can induce the formation of flower-like LiOH in the presence of water due to its unique porous structure and directional alignment of Mn-O centers. This work achieves the reversible formation and decomposition of LiOH in the presence of water, offering some insights into the practical application of semiopen Li-O2 batteries.

Size-Controlled Boron-Based Bifunctional Photocathodes for High-Efficiency Photo-Assisted Li-O2 Batteries.

Photo-assisted Li-O2 batteries are introduced as a promising strategy for reducing severe overpotential by directly employing photocathodes. Herein, a series of size-controlled single-element boron photocatalysts are prepared by the meticulous liquid phase thinning methods by combining probe and water bath sonication, and their bifunctional photocathodes in the photo-assisted Li-O2 batteries are systematically investigated. The boron-based Li-O2 batteries have shown incremental round-trip efficiencies as the sized reduction of boron under illumination. It is noteworthy that the completely amorphous boron nanosheets (B4 ) photocathode not only delivers an optimizing round-trip efficiency of 190% on the basis of the ultra-high discharge voltage (3.55 V) and ultra-low charge voltage (1.87 V) but also gives a high rate performance and ultralong durability with a round-trip efficiency of 133% after 100 cycles (200 h) compared with the other-sized boron photocathodes. This remarkable photoelectric performance of the B4 sample can be attracted to the synergistic effect on the suitable semiconductor property, high conductivity, and strengthened catalytic ability of boron nanosheets coated with ultrathin amorphous boron-oxides overlayer. This research can open a new avenue to facilitate the rapid development of high-efficiency photo-assisted Li-O2 batteries.

Chromium-doped inverse spinel electrocatalysts with optimal orbital occupancy for facilitating reaction kinetics of lithium-oxygen batteries.

Tailored electrocatalysts that can modulate their electronic structure are highly desirable to facilitate the reaction kinetics of oxygen evolution reaction (OER) and oxidation reduction reaction (ORR) in lithium-oxygen batteries (LOB). Although octahedron predominant inverse spinels (e.g., CoFe2O4) have been proposed as promising candidates for catalytic reactions, their performance has remained unsatisfactory. Herein, the chromium (Cr) doped CoFe2O4 nanoflowers (Cr-CoFe2O4) are elaborately constructed on nickel foam as a bifunctional electrocatalyst that drastically improves the performance of LOB. The results show that the partially oxidized Cr6+ stabilizes the cobalt (Co) sites at high-valence and regulates the electronic structure of Co sites, facilitating the oxygen redox kinetics of LOB due to their strong electron-withdrawing capability. Moreover, DFT calculations and ultraviolet photoelectron spectrometer (UPS) results consistently demonstrate that Cr doping optimizes the eg electron filling state of the active octahedral Co sites, significantly improves the covalency of Co-O bonds, and enhances the degree of Co 3d-O 2p hybrids. As a result, Cr-CoFe2O4 catalyzed LOB can achieve low overpotential (0.48 V), high discharge capacity (22030 mA h g-1) and long-term cycling durability (over 500 cycles at 300 mA g-1). This work promotes the oxygen redox reaction and accelerates the electron transfer between Co ions and oxygen-containing intermediates, highlighting the potential of Cr-CoFe2O4 nanoflowers as bifunctional electrocatalysts for LOB.

Modulating Electronic Structure with Copper Doping to Promote the Electrocatalytic Performance of Cobalt Disulfide in Li-O2 Batteries.

Introducing heteroatom into catalyst lattice to modulate its intrinsic electronic structure is an efficient strategy to improve the electrocatalytic performance in Li-O2 batteries. Herein, Cu-doped CoS2 (Cu-CoS2 ) nanoparticles are fabricated by a solvothermal method and evaluated as promising cathode catalysts for Li-O2 batteries. Based on physicochemical analysis as well as density functional theory calculations, it is revealed that doping Cu heteroatom in CoS2 lattice can increase the covalency of the CoS bond with more electron transfer from Co 3d to S 3p orbitals, thereby resulting in less electron transfer from Co 3d to O 2p orbitals of Li-O species, which can weaken the adsorption strength toward Li-O intermediates, decrease the reaction barrier, and thus improve the catalytic performance in Li-O2 batteries. As a result, the battery using Cu-CoS2 nanoparticles in the cathode exhibits superior kinetics, reversibility, capacity, and cycling performance, as compared to the battery based on CoS2 catalyst. This work provides an atomic-level insight into the rational design of transition-metal dichalcogenide catalysts via regulating the electronic structure for high-performance Li-O2 batteries.

Water-Trapping Single-Atom Co-N4 /Graphene Triggering Direct 4e- LiOH Chemistry for Rechargeable Aprotic Li-O2 Batteries.

Lithium-oxygen (Li-O2 ) batteries have received extensive attention owing to ultrahigh theoretical energy density. Compared to typical discharge product Li2 O2 , LiOH has attracted much attention for its better chemical and electrochemical stability. Large-scale applications of Li-O2 batteries with LiOH chemistry are hampered by the serious internal shuttling of the water additives with the desired 4e- electrochemical reactions. Here, a metal organic framework-derived "water-trapping" single-atom-Co-N4 /graphene catalyst (Co-SA-rGO) is provided that successfully mitigates the water shuttling and enables the direct 4e- catalytic reaction of LiOH in the aprotic Li-O2 battery. The Co-N4 center is more active toward proton-coupled electron transfer, benefiting - direction 4e- formation of LiOH. 3D interlinked networks also provide large surface area and mesoporous structures to trap ≈12 wt% H2 O molecules and offer rapid tunnels for O2 diffusion and Li+ transportation. With these unique features, the Co-SA-rGO based Li-O2 battery delivers a high discharge platform of 2.83 V and a large discharge capacity of 12 760.8 mAh g-1 . Also, the battery can withstand corrosion in the air and maintain a stable discharge platform for 220 cycles. This work points out the direction of enhanced electron/proton transfer for the single-atom catalyst design in Li-O2 batteries.