Recent Advances in Achieving High Energy/Power Density of Lithium–Sulfur Batteries for Current and Near-Future Applications

Abstract

Although lithium–sulfur batteries (LSBs) are promising next-generation secondary batteries, their mass commercialization has not yet been achieved primarily owing to critical issues such as the “shuttle effect” of soluble lithium polysulfides (LiPSs) and uncontrollable Li dendrite growth. Thus, most reviews on LSBs are focused on strategies for inhibiting shuttle behavior and achieving dendrite-free LSBs to improve the cycle life and Coulombic efficiency of LSBs. However, LSBs have various promising advantages, including an ultrahigh energy density (2600 Wh kg⁻¹), cost-effectiveness, environmental friendliness, low weight, and flexible attributes, which suggest the feasibility of their current and near-future practical applications in fields that require these characteristics, irrespective of their moderate lifespan. Here, for the first time, challenges impeding the current and near-future applications of LSBs are comprehensively addressed. In particular, the latest progress and novel materials based on their electrochemical characteristics are summarized, with a focus on the gravimetric/volumetric energy density (capacity), loading mass and sulfur content in cathodes, electrolyte-to-sulfur ratios, rate capability, and maximization of these advantageous characteristics for applications in specific areas. Additionally, potential areas for practical applications of LSBs are suggested, with insights for improving LSB performances from a different standpoint and facilitating their integration into various application domains.