Advances in Lithium–Sulfur Batteries: From Academic Research to Commercial Viability

Abstract

to sustain a continuous power supply for our daily life. [2] This is where rechargeable batteries can play a vital role in electrochemically storing and releasing the energy reversibly. [3] Additionally, as the majority of fossil fuel consumption is used for transportation, a shift from combustion engines to electric vehicles is essential in the 21st century. However, lithium-ion batteries, which have dominated the portable electronics over the past three decades, are unable to satisfy the high-energy requirement for electrical vehicles and next-generation energy storage. [2a,4] This is because the conventional lithium-ion batteries rely on the intercalation-type electrode materials and the lithium ions can only be intercalated topologically into certain specific sites, which limits their charge-storage capacity and energy density. [5] Therefore, exploring new battery chemistries beyond the horizon of current lithium-ion batteries is crucial for a sustainable future. [6] To realize a high energy density with new battery chemistries, seeking new types of electrode materials is a prerequisite. [7] Lithium metal, which has the highest theoretical specific capacity of 3860 mA h g −1 among the anode materials and the lowest electrochemical potential of −3.04 V versus the standard hydrogen electrode, is regarded as the "Holy Grail" anode material for next-generation batteries. [8] Sulfur, which is abundant, cheap, and environmentally benign, can offer a high theoretical specific capacity of 1675 mA h g −1 when paired with lithium metal, which is among the highest in solid cathode materials. [9] This is because the sulfur cathode undergoes a conversion reaction mechanism rather than the intercalation chemistry. Together with an average cell voltage of 2.15 V, the coupled lithium-sulfur (Li-S) battery can attain a high theoretical energy density of 2500 W h kg −1 , which is much higher than that of current lithium-ion batteries. [10] The earliest Li-S battery can be traced back to 1962 when Herbert and Ulam first introduced the concept of sulfur cathode (Figure 1). [11] Despite decades of research, the Li-S batteries had been long plagued with low discharge capacity and fast capacity decay upon cycling. Additionally, with the commercialization of lithium-ion batteries by Sony Co. in the 1990s, which have much more stable cycling performance and better safety, the research into Li-S batteries had once ceased for a period. [43] After 2000, as the rapid development of emerging applications such as electric vehicles and grid energy storage placed higher demands on the specific energy Lithium-ion batteries, which have revolutionized portable electronics over the past three decades, were eventually recognized with the 2019 Nobel Prize in chemistry. As the energy density of current lithium-ion batteries is approaching its limit, developing new battery technologies beyond lithiumion chemistry is significant for next-generation high energy storage. Lithiumsulfur (Li-S) batteries, which rely on the reversible redox reactions ...

Theoretical Predictions, Experimental Modulation Strategies, and Applications of MXene‐Supported Atomically Dispersed Metal Sites

“…The theoretical specific capacities recorded for the sulfur cathode and Li anode were 1675 and 3860 mAh g −1 , respectively, and the theoretical energy density recorded for the assembled LiS batteries was 2567 mAh g −1 . [ 101 ] The unsatisfactory reaction kinetics and rigorous shuttle effect observed for the soluble lithium polysulfides hinder the practical application of the sulfur cathodes. Yang and co‐workers attempted to solve these problems by designing a catalyst consisting of single Zn atoms supported on MXene (Zn SA /MXene) as a sulfur host.…”

Nitrogen-doped porous carbon fiber/vertical graphene as an efficient polysulfide conversion catalyst for high-performance lithium–sulfur batteries

“…1 One is that low conductivity of sulfur and lithium sulfide leads to slow electrochemical kinetics, and the other is the shuttle effect of polysulfide (Li 2 S n , 4 ≤ n ≤ 8) and a large volume change (∼80%) of sulfur leads to rapid capacity decay during the electrochemical charging and discharge process. 2,3…”

Mapping Techniques for the Design of Lithium‐Sulfur Batteries

“…Lithium sulfur (Li‐S) battery is on the edge of fulfilling its promises as the next‐generation energy storage system. [ 1,2 ] Efforts and progresses have been made to resolve the fundamental problems in Li‐S battery, including the poor conductivity of S and Li 2 S, volume expansion during cycling, shuttle effect of polysulfides (LiPSs), [ 3 ] and dendrite formation on the lithium metal anode. [ 4–6 ] Because of the complex conversion based reactions in Li‐S battery, various hypothesis and models about the reaction pathways are proposed by researchers, which are supported by every available characterization techniques and carefully designed methods.…”