An Advanced Lithium‐Sulfur Battery

Abstract

A lithium-sulfur battery employing a high performances mesoporous hard carbon spherules-sulfur cathode and a stable, highly conducting electrolyte is reported. The results demonstrate that the battery cycles with very high capacity, i.e., of the order of 750 mAh g − 1 with excellent retention during cycling. In addition, by exploiting the high conductivity of our selected electrolyte, the battery performs very well also at low temperature, i.e., delivering a capacity of 500 mAh g − 1 (S) at 0 ° C for over 170 charge- discharge cycles. We believe that these results may substantially contribute to the progress of the lithium-sulfur battery technology

Sulphur-impregnated flow cathode to enable high-energy-density lithium flow batteries

“…The interfacial resistance first decreased upon discharge to polysulphide phases (D1-D4) and markedly increased upon full discharge (D5). This suggests that the interfacial resistance decreases by transforming the insulating solid sulphur to soluble polysulphides, which improves the interfacial contacts between sulphur-containing species and carbon 22 , but significantly increases due to the formation of insulating film-like Li 2 S (refs 28,30,44,45). Reversibly, the interfacial resistance decreased after charging the catholyte to the polysulphide phase (C1-C3) and remained small at the end of the charging.…”

“…Preparation of the S/C composite. The S/C composite was prepared according to the well-established method for traditional solid sulphur electrodes [28][29][30][31][32][33][34][35][36][37][38] . Sulphur and KB were mixed with a mass ratio 22:1 in DME, followed by sonication using the SLPt Cell Disruptor (Branson, USA) for 30 min.…”

“…6e), the discharge product forms a continuous film that covers the entire composite and closes the pores. The film is attributed to Li-S solid discharge products such as Li 2 S (refs 28,30,44,45). An important open question arises as follows.…”

“…We show that exploiting the sulphur-impregnated catholyte uniformly integrates the active materials (solid sulphur) and the conductive carbon-percolating network (KB), which enhances the utilization of insulating sulphur. The sulphur-impregnated carbon composite flow-cathode structure is inspired by wellestablished strategies for traditional solid sulphur electrodes [28][29][30][31][32][33][34][35][36][37][38] . Third, an unexpected advantage of using S/C composite is that the viscosity of the S/C composite catholyte is significantly lower than the mechanically mixed S þ C catholyte (under the same S and carbon concentration, see Results).…”

Critical Link between Materials Chemistry and Cell-Level Design for High Energy Density and Low Cost Lithium-Sulfur Transportation Battery

“…8 A variety of porous carbons, polymers, metal oxides and functionalized graphenes have been developed in an attempt to contain the soluble polysulfide intermediates through both physical and chemical interactions. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] In addition to mitigating the polysulfide shuttle, engineered S cathodes have enhanced electronic conductivity and may accommodate the volume change in the cathode during cycling. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Other approaches have focused on designing new electrolytes with limited polysulfide solubility thereby suppressing the polysulfide shuttle leading to excellent coulombic efficiency and improved capacity retention.…”