Boosting Adsorption and Catalysis of Polysulfides by Multifunctional Separator for Lithium–Sulfur Batteries

Abstract

Lithium−sulfur (Li−S) batteries are considered promising energy storage technologies due to their high energy density and environmental friendliness. However, the unsatisfactory electrochemical performance mainly caused by dissolution and shuttling of polysulfides limits their application. Herein, a multifunctional separator, i.e., the sodium alginate (SA) fiber membrane with in situ loading of ZIF-67 attached on the polyacrylonitrile (PAN) matrix (ZIF-67/SA-PAN), is developed for Li−S batteries. On the basis of the synergistic adsorption and catalytic effect, ZIF-67/SA-PAN can inhibit the shuttling of polysulfides and promote fast transformation of the intercepted polysulfides, as revealed by in situ characterization and theoretical calculations. The ZIF-67/SA-PAN separator endows Li−S batteries with high reversible capacity (e.g., 797.4 mAh g −1 with a high sulfur loading of 5.45 mg cm −2 at 0.1 C) and long cycle life (500 cycles at 1 C). The ZIF-67/SA-PAN functional separator in this work can provide a facile and inexpensive approach to fabricate practical Li−S batteries.

Wide-Temperature Operation of Lithium–Sulfur Batteries Enabled by Multi-Branched Vanadium Nitride Electrocatalyst

“…The specific capacities of Li–S batteries using the MB-VN coating layer under 4.6 and 6.0 mg cm –2 sulfur are 970 and 936 mAh g –1 at 0.1 C, respectively, and they decrease to 727 and 615 mAh g –1 at 0.5 C, respectively. Notably, the above results are among the best as compared to those of recently published works (Figure i), − implying the great potential of using MB-VN-modified separators for practical applications.…”

Carbonized Polymer Dots Enhancing Interface Stability of LiNi0.8Co0.1Mn0.1O2 Cathodes

“…Figure S6a (Supporting Information) shows the Co XPS spectra of NCM811 and NCM811@1 wt% CPDs at ≈780.0 and 795.0 eV for Co 2p 3/2 and Co 2p 1/2 , respectively. [ 22 ] The results show that Co 3+ was well‐maintained after CPDs coating. As shown in Figure S6b (Supporting Information), the shape of O 1s spectra change weakly.…”

Integrating an In‐Plane Electron‐Conductive Separator to Enable Short‐Circuit Warning in Lithium–Sulfur Batteries

“…polysulfides, [24][25][26][27] which inevitably interfere with the indicators. On the other hand, compared with LIBs, lithium dendrites are prone to generate even without electrical abuse, triggering internal circuit short and thermal runaway of Li-S batteries.…”

“…Currently, the active strategies applied to the early warning of short circuits are aimed at conventional LIBs. [ 23 ] How effective these strategies can be directly transplanted into Li–S batteries remains to be verified, especially in the presence of shuttled polysulfides, [ 24–27 ] which inevitably interfere with the indicators. On the other hand, compared with LIBs, lithium dendrites are prone to generate even without electrical abuse, triggering internal circuit short and thermal runaway of Li–S batteries.…”