Will lithium-sulfur batteries be the next beyond-lithium ion batteries and even much better?

Lithium-ion batteries (LIBs) are undoubtedly the current working-horse in almost all portable electronic devices, electric vehicles, and even large-scale stationary energy storage. Given the problems faced by LIBs, a big question arises as to which battery(ies) would be the Beyond LIBs batteries. Among the front-runners, lithium-sulfur batteries (LSBs) have been extensively pursued owing to their intrinsically high energy density and extremely low cost. Despite the steady and sometimes exciting progress reported on sulfur chemistry and cell performance at laboratory scales over the past decade, one of the major bottlenecks is the poor cyclability. In this perspective, we examine the key challenges and opportunities faced by LSBs, as well as approaches at the materials, electrode/electrolyte and cell integration levels that can be taken to transform LSBs from a front-runner to a real leading champion in the pursuit of the Beyond LIBs. While the key new mechanistic insights are very important, we propose a set of the near-future research directions for both the liquid and solid state LSBs, where the currently on-going parallel pursuits of both liquid and solid LSBs will be converging. The liquid current will gradually be taken over by solid future in the expected LSBs commercialization in the coming decade.

Automated summary

Lithium-ion batteries are widely used in portable electronic devices, electric vehicles, and stationary energy storage, but there is a need for beyond lithium-ion batteries with higher energy density and lower cost. Lithium-sulfur batteries have been extensively pursued due to their high energy density, but poor cyclability remains a major challenge. This perspective examines the challenges and opportunities faced by lithium-sulfur batteries and proposes approaches at different levels to transform them into leading champions in the pursuit of beyond lithium-ion batteries. Suggestions for near-future research directions for both liquid and solid state lithium-sulfur batteries are also provided.