High‐Performance Li–O₂ Batteries with Controlled Li₂O₂ Growth in Graphene/Au‐Nanoparticles/Au‐Nanosheets Sandwich

Abstract

The working of nonaqueous Li–O2 batteries relies on the reversible formation/decomposition of Li2O2 which is electrically insulating and reactive with carbon and electrolyte. Realizing controlled growth of Li2O2 is a prerequisite for high performance of Li–O2 batteries. In this work, a sandwich‐structured catalytic cathode is designed: graphene/Au‐nanoparticles/Au‐nanosheets (G/Au‐NP/Au‐NS) that enables controlled growth of Li2O2 spatially and structurally. It is found that thin‐layer Li2O2 (below 10 nm) can grow conformally on the surface of Au NPs confined in between graphene and Au NSs. This unique crystalline behavior of Li2O2 effectively relieves or defers the electrode deactivation with Li2O2 accumulation and largely reduces the contact of Li2O2 with graphene and electrolyte. As a result, Li–O2 batteries with the G/Au‐NP/Au‐NS cathode exhibit superior electrochemical performance. A stable cycling of battery can last 300 times at 400 mA g−1 when the capacity is limited at 500 mAh g−1. This work provides a practical design of catalytic cathodes capable of controlling Li2O2 growth.

Ultrathin, Lightweight, and Wearable Li‐O2 Battery with High Robustness and Gravimetric/Volumetric Energy Density

“…Fortunately, the rechargeable aprotic lithium‐oxygen (Li‐O 2 ) battery has emerged as a very promising candidate due to its ultrahigh theoretical energy density . Although four flexible Li‐O 2 battery prototypes have been developed very recently, to achieve good wearability and robustness, especially in conjunction with high energy density, remains a daunting challenge due to the absence of effective components and favorable cell configurations: (1) lithium metal anode is problematic – the cracks generated after repetitive folding/bending would inevitably result in poor robustness and even short circuit and/or premature battery death; (2) assembly of a flexible Li‐O 2 battery still heavily rely on soft packaging fixation (e.g., shrinkable tube and aluminum soft packaging materials) and thick air diffusion layer (which serves as an important component for cell assembly, such as steel mesh, nickel foam, etc.…”

Continuous Synthesis of Hollow High‐Entropy Nanoparticles for Energy and Catalysis Applications

“…The Li-O 2 technology holds great promise as a post-Li-ion contender, however its development is hindered by low energy efficiency and poor cyclability. [24][25][26][27] Li-O 2 batteries employ the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the cathode, with both incurring high overpotentials during discharge and recharge, respectively, as well as serious stability concerns with all the cell components. [28][29][30] The overarching goal by the research community is therefore to find an efficient and stable catalyst to promote highly reversible ORR and OER during cycling.…”

An Overview of Engineered Graphene‐Based Cathodes: Boosting Oxygen Reduction and Evolution Reactions in Lithium– and Sodium–Oxygen Batteries

“…Gold has also been explored as ab ifunctionalcatalysti ns everal studies in the field of Li-O 2 cathodes. Thus, ac omplex synthetic approach was presented by Wane tal., [47] in which Au NPs were sandwiched between Au nanosheets (NS) and GNSs ( Figure 5a). The resulting materials howedadischarge capacity of 3347 mAh g À1 andw as stable for 170 and 300 cycles (400 mA g À1 )u nder ac apacity limitation regime of 500 and 1000 mAh g À1 ,r espectively (Figure 5b and c).…”