296,889 research outputs found
Accelerating S↔Li2S Reactions in Li–S Batteries through Activation of S/Li2S with a Bifunctional Semiquinone Catalyst
No full textThe reaction rate bottleneck during interconversion between insulating S8 (S) and Li2S fundamentally leads to incomplete conversion and restricted lifespan of Li−S battery, especially under high S loading and lean electrolyte conditions. Herein, we demonstrate a new catalytic chemistry: soluble semiquinone, 2-tertbutyl-semianthraquinone lithium (Li+TBAQ⋅−), as both e-/Li+ donor and acceptor for simultaneous S reduction and Li2S oxidation. The efficient activation of S and Li2S by Li+TBAQ⋅− in the initial discharging/charging state maximizes the amount of soluble lithium polysulfide, thereby substantially improve the rate of solid–liquid-solid reaction by promoting long-range electron transfer. With in situ Raman spectra and theoretical calculations, we reveal that the activation of S/Li2S is the rate-limiting step for effective S utilization under high S loading and low E/S ratio. Beyond that, the S activation ratio is firstly proposed as an accurate indicator to quantitatively evaluate the reaction rate. As a result, the Li−S batteries with Li+TBAQ⋅− deliver superior cycling performance and over 5 times higher S utilization ratio at high S loading of 7.0 mg cm−2 and a current rate of 1 C compared to those without Li+TBAQ⋅−. We hope this study contributes to the fundamental understanding of S redox chemical and inspires the design of efficient catalysis for advanced Li−S batteries.No Full Tex
LI A 5.5 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location A 5.5 m/s
LI UT 7.4 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location UT 7.4 m/s
LI AP 9.3 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location AP 9.3 m/s
LI B 7.4 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location B 7.4 m/s
LI UT 5.5 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location UT 5.5 m/s
LI UT 9.3 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location UT 9.3 m/s
LI C 5.5 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location C 5.5 m/s
LI R 9.3 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location R 9.3 m/s
LI F 9.3 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location F 9.3 m/s
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