Challenges and Strategy on Parasitic Reaction for High‐Performance Nonaqueous Lithium–Oxygen Batteries

Abstract

is restricted to their inferior energy densities (≈250 Wh kg −1) due to intercalation chemistry. Consequently, "beyond Li-ion batteries" such as lithium-sulfur batteries and metal-air batteries, which have fundamental discrepant energy storage mechanism, have been attracted worldwide attention recently. [4,5] Of all the candidates, rechargeable lithium-oxygen battery (LOB) is considered to be one of the most fascinating next-generation batteries with extremely high theoretical energy density (≈3500 Wh kg −1). [6,7] The low-cost and environmental positive active material oxygen originates from air, endowing LOBs more attractive to satisfy the soaring demand of large-scale energy storage system. Generally, there are four architecture systems of LOBs determined by different electrolyte: aqueous, nonaqueous, hybrid, and all-solid-state. [8-11] In 1996, Abraham and Jiang first reported the rechargeable lithium-oxygen battery consisted of Li metal anode, solid polymer electrolyte membrane, and composite carbon cathode. [12] After ten years, nonaqueous LOBs actually caught worldwide attention due to the outstanding capacity and reversibility. [6] A typical nonaqueous lithium-oxygen battery comprises a metallic Li anode, organic electrolyte containing Li salt, a separator, and a porous gas diffusion cathode loading with catalysts (Figure 1). [13] Generally, the electrochemical reactions of nonaqueous lithium-oxygen battery can be described as following equations [14-16] Overall reaction E 2Li O Li O 2.96 V vs Li/Li 2 2 2 () + ↔°= + (1) Cathodic process (oxygen reduction reaction (ORR))

Single Semi‐Metallic Selenium Atoms on Ti3C2 MXene Nanosheets as Excellent Cathode for Lithium–Oxygen Batteries

“…However, the low round-trip efficiency, poor rate capability, and inferior cycle durability originated from sluggish electrochemical kinetics of discharge lithium peroxide (Li 2 O 2 ) product, have become the bottle-neck for the large-scale commercialization of LOBs. [1][2][3][4] Employing highly efficient electrocatalysts which stability. [22] Our group also reported a pioneering gas-migrationtrapping strategy to fabricate a MOF-derived nitrogen-doped carbon nanosheets confining Co SACs.…”

“…However, the low round‐trip efficiency, poor rate capability, and inferior cycle durability originated from sluggish electrochemical kinetics of discharge lithium peroxide (Li 2 O 2 ) product, have become the bottle‐neck for the large‐scale commercialization of LOBs. [ 1–4 ] Employing highly efficient electrocatalysts which possess modulated electron structure and enhanced catalytic activity has been regarded as a feasible strategy to promote oxygen reduction reaction (ORR) and oxygen evolution reduction (OER) kinetics of LOBs. [ 5,6 ] Maximizing atomic utilization to improve catalytic activity has become a strategic measure for promoting the large‐scale application of electrocatalytic system.…”

Designing porous and stable Au-coated Ni nanosheets on Ni foam for quasi-symmetrical polymer Li–air batteries

“…[20][21][22] However, the carbon in these catalysts is easily attacked by super oxygen molecules (O 2 À ), even promoting side-product formation (such as Li 2 CO 3 ) over cycling, which can lead to inferior electrochemical stability. 23 Recently, carbon-free cathodes have been investigated due to their good oxidization resistance, but many of them lack pores or are just based on low-activity transition metal (TM)-containing catalysts, harming the performance of the corresponding Li-air cells. [24][25][26] On the other hand, the metallic Li anodes in Li-air batteries also face many undesirable problems, including uncontrolled dendritic/dead Li formation, large volume changes, and serious corrosion.…”

Advanced Engineering for Cathode in Lithium–Oxygen Batteries: Flexible 3D Hierarchical Porous Architecture Design and Its Functional Modification

“…These binders suffer from severe decomposition, especially with the presence of reactive oxygen species due to their weak electrochemical stability. [22,24] So the application of binders has been identified as one of the chief culprits in battery component incompatibility and the primary cause of premature battery death. [3] In this research, we create a well-designed, free-standing composite structure where surface-sprouted carbon nanofibers (CNFs) networks serve as superior cathodic catalysts, and flexible 3D porous graphene foam (PGF) serves as substrate without the need for extra binders or cathodic substrates.…”

“…Cathode is identified as the most important part of a LOBs system because it significantly impacts the Li 2 O 2 formation and decomposition process, which directly determines battery performance. [22] However, the optimization of cathode is an intricate project, which is identifies as two major considerations: catalyst selection and nanostructure design. In selecting the catalyst, it must consider the kinetic and thermodynamic activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER).…”