Integrated high-sulfur-loading polysulfide/carbon cathode in lean-electrolyte cell toward high-energy-density lithium–sulfur cells with stable cyclability

Abstract

The commercialization of high-energy-density lithium–sulfur batteries depends on the development of a high-sulfur-loading cathode with high electrochemical utilization and stability in lean-electrolyte cells. However, the desired cell-design parameters often exacerbate...

A low-self-discharge high-loading polysulfide cathode design for lithium–sulfur cells

“…However, although great advances in battery technology and dynamic electrochemical performance during cycling have been achieved in recent years, 23–26 the static electrochemistry of the self-discharge behavior of the lithium–sulfur cell has been rarely studied. Moreover, the severe self-discharge of lithium–sulfur cells during long-term storage has been even less studied, despite the fact it worsens as the sulfur loading and sulfur content in the cathode configuration are increased, 18,27–29 which occurs because the solid-state active materials (sulfur) react with lithium ions in the electrolyte system and form polysulfides.…”

“…In addition, we developed a low-self-discharge lithium–sulfur cell with a polysulfide cathode. 26,36,37 The cathode consisted of a well-carbonized electrospun nanofiber substrate and polysulfide active material. The designed cathode had a high areal sulfur loading (4.03 mg cm −2 ) and high sulfur content (66.7 wt%) (including the full cathode).…”

Electrolessly tin-plated sulfur nanocomposite for practical lean-electrolyte lithium–sulfur cells with a high-loading sulfur cathode

“…Therefore, we demonstrate the application of the electroless plating synthesis method for designing a novel tin-plated sulfur nanocomposite to achieve excellent cell design parameters ( i.e. , a high sulfur loading of >5 mg cm −2 , a high sulfur content of >50 wt%, and a low electrolyte-to-sulfur ratio of <5 μL mg −1 ) 4–7,24 and outstanding cell performance values ( i.e. , a high areal capacity of >4 mA h cm −2 , an energy density of >10 mW h cm −2 , and a low electrolyte-to-capacity ratio of <5 μL mA h −1 ).…”

“…22,23 However, the use of additional cell components reduces the sulfur content in the cathode, and the use of high-porosity host materials and cell components results in the rapid consumption of a large amount of electrolyte in the cell. 4–6,24 These further challenge the development of high-energy-density lithium–sulfur, which requires a high and stable utilization of a large amount of sulfur in the lean electrolyte with a low electrolyte-to-sulfur ratio. Moreover, although the required cell design progress would improve the feasibility of the lithium–sulfur technology, the high-loading sulfur cathode often encounters high resistance and strong polysulfide shuttling, and the lean-electrolyte cell shows poor lithium-ion transfer.…”

“…The resulting poor cyclability results in low stability and short cycle life, which restricts the study and development of critical parameters for lithium–sulfur batteries to be practically viable. 20–26…”