A polysulfides adsorption strategy through cation-anion interactions for achieving high-safety lithium-sulfur batteries in multiple scenarios
writer：Xinxin Dong，Xin Tong
keywords：Lithium-sulfur battery, Coating for sparator, Boron nitride, Redox kinetic, Fire safety
source：期刊
Issue time：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(yīng)用受到多硫化物（LiPS）的穿梭效應(yīng)、緩慢反應(yīng)動(dòng)力學(xué)和消防安全問(wèn)題等挑戰(zhàn)的阻礙。在這項(xiàng)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(shí)現(xiàn)了LSB的多種應(yīng)用場(chǎng)景。具體而言，通過(guò)N在ChBN表面對(duì)LiPSs中S+n-的強(qiáng)化學(xué)吸附，構(gòu)建了一種創(chuàng)新的陽(yáng)離子-陰離子相互作用策略。此外，氮化硼和氮對(duì)吸附催化顯示出協(xié)同作用，進(jìn)一步促進(jìn)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(yōu)異的循環(huán)穩(wěn)定性（在2C下500次循環(huán)中，每次循環(huán)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(nèi)使用，在60°C時(shí)的容量為1208 mA h/g，在-20°C時(shí)為919 mA h/g。此外，ChBN的存在通過(guò)凝聚相阻燃機(jī)制有效地提高了袋式電池的防火安全性。這種簡(jiǎn)單的ChBN制造工藝是有效的，有利于大規(guī)模制造，為開(kāi)發(fā)高安全性的LSB提供了一種可行的方法。