Fundamentally altering the essential properties of a material itself is always of great interest but challenging as well. Herein, we demonstrate a simple tellurium doping method to intrinsically reshape the electronic properties of the sulfur and manipulate the kinetics of Li–S chemistry for improving the performance of Li–S batteries. DFT calculation indicates that Te doping can effectively facilitate the lithiation/delithiation reactions and lower the lithium ion diffusion energy barrier in Li2S. Additionally, electrochemical studies prove that the reaction kinetics of Li–S chemistry and cycling performance of Li–S batteries have been significantly improved with Te dopants. An exceptional specific capacity of ∼656 mA h g–1 and a high Coulombic efficiency of ∼99% have been achieved at 5 A g–1 even after 1000 cycles. More importantly, the capability to manipulate the intrinsic properties of materials and explore the synergistic effects between conventional strategies and element doping provides new avenues for Li–S batteries and beyond.

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to low round-trip efficiency as well as limited capacity. And cathode clogging arising from insulated, insoluble discharge products accumulation blocks the electron transfer and oxygen/Li + diffusion, resulting in a high overpotential for the electrochemical reactions, which will trigger parasitic reactions such as electrolyte oxidation. [5] As cathode corrosion aggravates, the batteries deliver poor cycle stability.Over the past few decades, numerous studies have intensively focused on cathodes and catalysts to address the main challenges in the Li-O 2 batteries. [6][7][8][9][10][11][12] Single atom materials with superior catalytic properties and unique electronic structure are promising electrode materials for Li-O 2 batteries. [13][14][15][16][17][18][19] Single atoms serving as catalytic centers effectively promote the slow kinetic process of lithium oxygen batteries. [20] However, the catalysis of immobile single-atom catalysts is limited only for Li 2 O 2 particles directly deposited on the surface of the catalysts without oxidizing the electronically isolating Li-peroxide layers, which leads to low round-trip efficiency and poor cycle stability. [21][22][23] To address this concern, many attempts have been made to effectively promote the decomposition of Li 2 O 2 . Recently, redox mediators, a kind of liquid catalysts have been developed for facilitating the oxidation of Li 2 O 2 upon charging. [24,25] The redox mediators will first be oxidized in solution phase to form oxidized species during charge process, followed by chemically oxidizing the Li 2 O 2 from the solution side so that the catalytic effect can be exerted on all the Li 2 O 2 that is formed during the ORR process. [26] Lithium bromide (LiBr) was first proposed by Sun and coworkers as a RM in Li-O 2 batteries to reduce the OER overvoltage. [27] Br − can be oxidized upon charging at 3.48 V to Br 3 − and further be oxidized to Br 2 at 4.0 V, both of which can readily react with Li 2 O 2 to form Br − , Li + , and O 2 . [28,29] However, undesirable shuttle phenomenon, that is Br 2 or Br 3 − diffuse to and react with Li anode, resulting in the poor cycle stability and round-trip efficiency. [26] Herein, we report the successful combination of single-atom cobalt anchored in porous N-doped hollow carbon spheres Lithium-oxygen (Li-O 2 ) batteries with ultrahigh theoretical energy density have attracted widespread attention while there are still problems with high overpotential and poor cycle stability. Rational design and application of efficient catalysts to improve the performance of Li-O 2 batteries is of significant importance. In this work, Co single atoms catalysts are successfully combined with redox mediator (lithium bromide [LiBr]) to synergistically catalyze electrochemical reactions in Li-O 2 batteries. Single-atom cobalt anchored in porous N-doped hollow carbon spheres (CoSAs-NHCS) with high specific surface area and high catalytic activity are utilized as cathode material. However, the potential performances of batteries are difficult to...

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