New insights into designation of single-ion conducting gel polymer electrolyte for high-performance lithium metal batteries

Conductive Carbon Fibrous Interlayer Embedded with MoS2@CNT Composites for Mitigating Polysulfide Shuttling by Absorption and Catalysis in Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) have emerged as promising energy storage systems due to their high energy density, low cost, and environmental friendliness. However, the "shuttle effect" of lithium polysulfides (LiPSs) leads to rapid capacity decay and poor cycle stability in LSBs, hindering further development and application of LSBs. In addition, it is difficult for existing strategies to provide effective adsorption and catalytic properties for polysulfides while simultaneously ensuring rapid ion transport. To address this issue, a composite film made of carbon fibers embedded with MoS2@CNT is proposed as an interlayer between the separator and the cathode. Results show that such a conductive interlayer can effectively capture LiPSs and catalyze their transformation. The as-assembled LSBs deliver an initial discharge-specific capacity of 1179.03 mAh/g at 0.5 C, and a capacity of 1086.33 mAh/g remains after 100 cycles. During long-term cycling tests, the LSBs show discharge capacities of 463.13 mAh/g with a decay rate per cycle of 0.07% after 500 cycles at 3 C, representing a reduction of 0.06% compared to that of commercial batteries (0.13%). This work demonstrates the potential of the independent conductive interlayer design of carbon fibrous films embedded with MoS2@CNT composites for enhancing battery performance. The film can not only provide an efficient conductive network for accelerating ion transport but also suppress the shuttle effect and catalyze the transformation of LiPSs, boosting electrochemical reaction kinetics.

Towards ambient temperature operation of Li metal batteries using UV-Crosslinked single-ion electrospun electrolytes

In spite of the fact that lithium metal batteries (LMBs) facilitate the diversification of energy storage technologies, their electrochemical reversibility and stability have long been constrained by side reactions and lithium dendrite problems. While single-ion conducting polymer electrolytes (SICPEs) possess unique advantages of suppressing Li dendrite growth, they deal with difficulties in practical applications due to their slow ion transport in general application scenarios at ∼25 °C. In this study, we develop novel bifunctional lithium salts with negative sulfonylimide (-SO₂N(^-)SO₂-) anions mounted between two styrene reactive groups, which is capable of constructing 3D cross-linked networks with multiscale reticulated ion nanochannels, resulting in the uniform and rapid distribution of Li⁺ ions in the crosslinked electrolyte. To verify the feasibility of our strategy, we designed PVDF-HFP-based SICPEs and the obtained electrolyte exhibits high thermal stability, outstanding Li⁺ transference number (0.95), pleasing ionic conductivity (0.722 mS cm^-1), and broad chemical window (greater than5.85 V) at ambient temperature. As a result of the electrolyte structural merits, the Li||LFP cells displayed excellent cycling stability (96.4% reversible capacities after 300 cycles at 0.2C) without additional auxiliary heating. This ingenious strategy is expected to providing a new perspective for advanced performance and high safety LMBs.