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The lithium metal anode is notoriously unstable and reactive to electrolytes, forming brittle solid‐electrolyte interphase (SEI) layers with uneven distribution, exacerbating Li dendrites that ultimately limit the battery life. Here, this work passivates Li metal with electrolyte‐swellable polymer nanolayers deposited monolithically by the initiated chemical vapor deposition (iCVD) to reinforce the native SEI layers and stabilize their interface. The 100 nm iCVD poly(dimethylaminomethyl styrene) (pDMAMS) layer is swelled by 264% under a carbonate electrolyte, establishing the electrolyte‐filled soft scaffold for Li‐ion transport. Notably, the solvogel accommodates homogeneous Li2O‐free and Li2CO3‐rich native SEI layers, providing a record‐high Li‐ion transference number of 0.95 and ionic conductivity of 6.54 mS cm−1. The developed pDMAMS‐Li anodes extend the cycle life by 550% in Li–Li symmetric cells and 600% in LiNi0.6Mn0.2Co0.2O2 full cells compared to pristine Li metal. The mechanistic details of the swollen‐soft‐scaffold strategy are elucidated by depth profile analysis of the pDMAMS homopolymer compared to pDMAMS/electrolyte‐phobic copolymers, providing new insights to manage the interface of liquid‐state electrolyte and solid‐state Li metal by using a novel class of bifunctional solvogel. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have been increasingly studied due to sodium (Na) being an inexpensive ionic resource (Na) and their battery chemistry being similar to that of current lithium-ion batteries (LIBs). However, SIBs have faced substantial challenges in developing high-performance anode materials that can reversibly store Na+ in the host structure. To address these challenges, molybdenum sulfide (MoS2)-based active materials have been considered as promising anodes, owing to the two-dimensional layered structure of MoS2 for stably (de)inserting Na+. Nevertheless, intrinsic issues of MoS2—such as low electronic conductivity and the loss of active S elements after a conversion reaction—have limited the viability of MoS2 in practical SIBs. Here, we report MoS2 embedded in carbon nanofibers encapsulated with a reduced graphene oxide (MoS2@CNFs@rGO) composite for SIB anodes. The MoS2@CNFs@rGO delivered a high capacity of 345.8 mAh g−1 at a current density of 100 mA g−1 for 90 cycles. The CNFs and rGO were synergistically taken into account for providing rapid pathways for electrons and preventing the dissolution of S sources during repetitive conversion reactions. This work offers a new point of view to realize MoS2-based anode materials in practical SIBs. [ABSTRACT FROM AUTHOR]

Silicon-coated molybdenum sulfide nanosheets were prepared in a thin-film shape (Si–MoS 2 TFs) through metal organic chemical vapor deposition (MOCVD) and radio frequency (RF) sputtering. By using MOCVD, the MoS 2 thin films composed of nanosheets were vertically grown on stainless steel substrates. To address the problem of polysulfide dissolution and shuttling effect of MoS 2 during discharge and charge reactions in thin-film Li-ion batteries, the entire surfaces of MoS 2 TFs were covered with silicon layers using RF sputtering. Compared with pristine MoS 2 TFs without protection, the Si–MoS 2 TFs showed excellent reversibility with a high capacity of ∼2000 mAh g−1 for 500 cycles in thin-film Li-ion batteries. Both materials – MoS 2 and Si – were synergistically taken into account to enhance the ability to store Li ions in the host structures and complement each other during repeated conversion and alloying reactions. The underlying reaction principle was elucidated, which provides insight into developing MoS 2 -based thin-film cathodes. [ABSTRACT FROM AUTHOR]