A Facile Immobilization Strategy for Soluble Phosphazene to Actualize Stable and Safe Lithium-Sulfur Batteries
作者：Tao Zhu , Dongli Chen , Guoqing Liu , Peng Qi , Xiaoyu Gu , Hongfei Li , Jun Sun , Sheng Zhang
關(guān)鍵字：可溶性磷腈的簡便固定化策略實(shí)現(xiàn)穩(wěn)定安全的鋰硫電池
論文來源：期刊
發(fā)表時(shí)間：2022年
Lithium–sulfur batteries (LSBs) have attracted extensive attention owing to their high energy density and abundant sulfur resources. However, LSBs are still restricted by the unsatisfactory electrochemical performance resulting from the shuttle effect of lithium polysulfide (LiPSs), and the potential fire hazard caused by inflammable ether electrolytes and polyolefin separators. Herein, a facile immobilization strategy for hexachlorocyclotriphosphazene (HCCP) is creatively applied to address the above issues simultaneously. Insoluble HCCP cross-linked microspheres (H-CMP) are firstly obtained at ambient temperature using tannic acid (TA) as a cross-linking agent and then a multifunctional separator coating is constructed based on H-CMP. The released phosphorus-related radicals from H-CMP in wide temperatures effectively prevent the combustion of electrolytes and separators, and hence improve the fire safety of the Li–S pouch cell. Furthermore, H-CMP availably chemisorbs LiPSs to interdict the shuttle effect, thereby dramatically improving the electrochemical performance of LSBs. The effectiveness of this strategy is also verified in high sulfur loading (6.38 mg cm-2), high temperature (50 °C), and Li–S pouch cells. More importantly, H-CMP exhibits sufficient stability for Li metal and suppression of Li dendrites. This facile immobilization strategy for multifunctional phosphazenes provides a competitive option for the large-scale fabrication of high-safety and high-performance LSBs.
鋰硫電池（LSBs）因其高能量密度和豐富的硫資源而受到廣泛關(guān)注。然而，LSBs仍然受到多硫化鋰（LiPSs）的穿梭效應(yīng)導(dǎo)致的不理想的電化學(xué)性能以及易燃的醚電解質(zhì)和聚烯烴隔膜引起的潛在火災(zāi)隱患的限制。在此，一種簡便的六氯環(huán)三磷腈（HCCP）固定化策略被創(chuàng)造性地應(yīng)用于同時(shí)解決上述問題。首先以單寧酸（TA）為交聯(lián)劑，在常溫下獲得不溶性HCCP交聯(lián)微球（H-CMP），然后構(gòu)建基于H-CMP的多功能隔膜涂層。H-CMP在寬溫度下釋放的磷相關(guān)自由基有效地防止了電解質(zhì)和隔膜的燃燒，從而提高了Li-S軟包電池的防火安全性。此外，H-CMP 有效地化學(xué)吸附 LiPS 以阻止穿梭效應(yīng)，從而顯著提高 LSB 的電化學(xué)性能。該策略的有效性也在高硫負(fù)載（6.38 mg cm-2 )、高溫 (50 °C) 和 Li-S 軟包電池。更重要的是，H-CMP對鋰金屬表現(xiàn)出足夠的穩(wěn)定性和抑制鋰枝晶。這種用于多功能磷腈的簡便固定策略為大規(guī)模制造高安全性和高性能 LSB 提供了競爭選擇。