A polysulfides adsorption strategy through cation-anion interactions for achieving high-safety lithium-sulfur batteries in multiple scenarios
作者：Xinxin Dong，Xin Tong
關鍵字：Lithium-sulfur battery, Coating for sparator, Boron nitride, Redox kinetic, Fire safety
論文來源：期刊
發表時間：2024年
The widespread application of lithium-sulfur batteries (LSBs) is hindered by challenges such as the shuttle effect of polysulfides (LiPSs), slow reaction kinetics, and fire safety concerns. In this study, surface-functionalized boron nitride nanosheets (ChBN) are prepared and employed as functional separator coatings, enabling multiple application scenarios of LSBs. Specifically, a creative strategy of cation-anion interactions is constructed through the strong chemisorption of N on the ChBN surface to S+n- in LiPSs. In addition, the boron nitride and N show synergistic effects on adsorption-catalysis, further facilitating the rapid and sufficient deposition of Li+2S. The prepared LSBs with ChBN + SP/PP separators exhibit excellent cycle stability (an ultralow capacity degradation of 0.034 % per cycle over 500 cycles at 2C). These LSBs are available in a wide temperature range of ?20 to 60 °C, offering a capacity of 1208 mA h/g at 60 °C and 919 mA h/g at ?20 °C. Furthermore, the presence of ChBN effectively improves the fire-safety of pouch batteries through the condensed-phase flame retardant mechanism. This simple fabrication process of ChBN is effective and favorable for large-scale manufacturing, which provides a feasible method for the development of high-safety LSBs.
鋰硫電池（LSB）的廣泛應用受到多硫化物（LiPS）的穿梭效應、緩慢反應動力學和消防安全問題等挑戰的阻礙。在這項研究中，制備了表面功能化的氮化硼納米片（ChBN），并將其用作功能性隔膜涂層，實現了LSB的多種應用場景。具體而言，通過N在ChBN表面對LiPSs中S+n-的強化學吸附，構建了一種創新的陽離子-陰離子相互作用策略。此外，氮化硼和氮對吸附催化顯示出協同作用，進一步促進了Li+2S的快速和充分沉積。制備的具有ChBN+SP/PP隔膜的LSB具有優異的循環穩定性（在2C下500次循環中，每次循環的超低容量退化為0.034%）。這些LSB可在-20至60°C的寬溫度范圍內使用，在60°C時的容量為1208 mA h/g，在-20°C時為919 mA h/g。此外，ChBN的存在通過凝聚相阻燃機制有效地提高了袋式電池的防火安全性。這種簡單的ChBN制造工藝是有效的，有利于大規模制造，為開發高安全性的LSB提供了一種可行的方法。