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Lithium–sulfur (Li–S) batteries with high sulfur loading are urgently required in order to take advantage of their high theoretical energy density. Ether‐based Li–S batteries involve sophisticated multistep solid–liquid–solid–solid electrochemical reaction mechanisms. Recently, studies on Li–S batteries have widely focused on the initial solid (sulfur)–liquid (soluble polysulfide)–solid (Li2S2) conversion reactions, which contribute to the first 50% of the theoretical capacity of the Li–S batteries. Nonetheless, the sluggish kinetics of the solid–solid conversion from solid‐state intermediate product Li2S2 to the final discharge product Li2S (corresponding to the last 50% of the theoretical capacity) leads to the premature end of discharge, resulting in low discharge capacity output and low sulfur utilization. To tackle the aforementioned issue, a catalyst of amorphous cobalt sulfide (CoS3) is proposed to decrease the dissociation energy of Li2S2 and propel the electrochemical transformation of Li2S2 to Li2S. The CoS3 catalyst plays a critical role in improving the sulfur utilization, especially in high‐loading sulfur cathodes (3–10 mg cm−2). Accordingly, the Li2S/Li2S2 ratio in the discharge products increased to 5.60/1 from 1/1.63 with CoS3 catalyst, resulting in a sulfur utilization increase of 20% (335 mAh g−1) compared to the counterpart sulfur electrode without CoS3.

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alternatives to next-generation batteries, have attracted extensive attention due to their high energy density and low cost. Metallic Li is considered as the ultimate choice of anode material for LMBs, owing to its ultrahigh theoretical capacity (3860 mAh g −1 ) and lowest electrochemical potential (−3.04 V vs the standard hydrogen electrode), [2] LMBs were pioneered during the 1970s, but they have not been successfully commercialized due to the significant safety concerns [3][4][5] associated with Li-dendrite growth during the repeated Li plating/ stripping process. The challenges of commercial application of metallic Li anodes can be summarized as follows: 1) Li tends to deposit unevenly to form dendritic and mossy-like morphology on the electrode during electrochemical cycling, which can subsequently penetrate the separator and cause internal short-circuits and thermal runaway. The dendritic Li could also be isolated from the bulk Li or current collector during the stripping process, becoming "dead Li" due to the absence of electronic contact, which leads to increased resistance, fading capacity, and short cycle life. [6] 2) The side reaction between Li and liquid electrolyte results in the formation of a solid electrolyte interphase (SEI) layer on the electrode surface. The unstable SEI layer is very fragile and easily fractured during the Li plating/stripping process. As a result, fresh Li is exposed and further consumes more electrolyte to form new SEI. This repetitive process endlessly consumes both Li and electrolyte, leading to growing interfacial resistance and decreasing Coulombic efficiency (CE). [7] 3) Owing to its "hostless" nature, Li metal undergoes a relatively infinite volume change during electrochemical cycling. This phenomenon causes significant challenges as it can often cause damage to the SEI during plating/stripping. [3] Among all the challenges of the Li-metal anode, the SEI plays a crucial role as a passivation layer to prevent further reactions between Li and electrolyte, hence improving electrochemical performance. A self-formed SEI is generally composed of the stacking of many small domains, including LiF, Li 2 O, Li 2 CO 3 , and organic Li compounds, with heterogeneous composition, ionic conductivities, and mechanical properties. [8] However, the deposition of dendritic or mossy-like Li still occurs during Metallic Li is considered as one of the most promising anode materials for next-generation batteries due to its high theoretical capacity and low electrochemical potential. However, its commercialization has been impeded by the severe safety issues associated with Li-dendrite growth. Non-uniform Li-ion flux on the Li-metal surface and the formation of unstable solid electrolyte interphase (SEI) during the Li plating/stripping process lead to the growth of dendritic and mossy Li structures that deteriorate the cycling performance and can cause short-circuits. Herein, an ultrathin polymer film of "polyurea" as an artificial SEI layer for Li-metal anodes via molecular-layer deposit...