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High-energy electrochemical storage containing earth abundant materials could be a choice for future battery development. Recent research reports indicated the possibility of room-temperature sodium-ion–sulfur chemistry for large storage including smart grids. Here, we report a room-temperature sodium–sulfur battery cathode that will address the native downsides of a sodium–sulfur battery, such as polysulfide shuttling and low electrical conductivity of elemental sulfur. In this Letter, we use a sustainable route which ensures a large sulfur confinement (i.e., ∼90 wt %) in the cathode structure. The sulfur-embedded polymer is realized via thermal ring-opening polymerization of benzoxazine in the presence of elemental sulfur (CS90) and later composite with reduced graphene oxide (rGO). The resulting CS90 allows a homogeneous distribution of sulfur due to in situ formation of the polymer backbone and allows maximum utilization of sulfur. This unique electrode structure bestows CS90–rGO with an excellent Coulombic efficiency (99%) and healthy cycle life.

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Room-temperature sodium−sulfur (RT Na−S) battery cathodes suffer from poor conductivity, rapid dissolution of intermediate products, and potentially destructive volume change during cycling. The optimal way to minimize these problems could be a construction of a nanocomposite cathode scaffold combining different components selected for their particular functions. Here, we have combined the excellent electronic conductivity of reduced graphene oxide, polysulfide adsorption ability of the ultrafine manganese oxide nanocrystals, rapid ion/electron dissemination efficiency of nanosized sulfur, and outstanding mechanical stiffness and good electrical conductivity of Na alginate/polyaniline hybrid binder in a single electrode heterostructure. At 0.2 A g −1 , an RT Na−S battery containing the freestanding cathode delivers an initial specific cap acity of 631 mA h g −1 . By delivering a nominal discharge voltage of 1.81 V, our Na−S batteries bestow a high specific energy of 737 W h kg −1 at the 2nd cycle and 660 W h kg −1 was retained after 50 cycles. The effect of the amount of electrolyte additive is also well demonstrated in this study. The electrode fabrication process provides a new approach to tailor the design and preparation of effective cathodes for the room-temperature sodium−sulfur batteries.

Capacity and stability enhancement has been observed for MoSe2 covered with N, P-doped rGO sheets. The sodiation behaviour was also investigated through different ex situ studies.

Room-temperature sodium–sulfur (RT Na–S) batteries offer the potential for inexpensive stationary energy storage at the grid and local level. However, their practical performance remains far from theoretical due to sluggish reaction kinetics, which limits both their energy and their rate characteristics. To overcome this, a conceptually new mechanism is demonstrated on the basis of the catalysis by stabilized free-radical species, as indicated by electron spin resonance measurements, generated on the surface of a Na2S6 catholyte-infiltrated activated carbon cloth cathode. X-ray photoelectron spectroscopy characterizations reveal that free-radical catalysis promotes reduction to end-discharged products, via a surface-bound intermediate state, ACC–S3 –. Due to this free-radical catalytic activity, our RT Na–S cell achieves a high nominal cell potential of 1.85 V. At a rate of 0.5 C, the Na–S cell delivers a high specific capacity of 866 mA h g(S) –1 and retains 678 mA h g(S) –1 after 700 cycles. The concept of a free-radical mechanism, as described herein, could be adapted to enhance the electrochemical kinetics of other energy storage devices that involve radical intermediate species.

Room‐temperature sodium–sulfur (RT Na–S) batteries are among the ideal candidates for grid‐scale energy storage due to their high theoretical energy density. However, rapid dissolution of polysulfides along with extremely slow redox kinetics lead to a low practical cell capacity and inferior cycling stability, inhibiting their practical applications. Herein, an innovative design strategy is introduced for a chemical and structural synergistic immobilization of sodium‐polysulfides in the cathode structure. An aluminum oxyhydroxide (AlOOH) nanosheets decorated sulfur/carbon black nanocomposite (S@CB@AlOOH) is used as an efficient cathode material for stable RT Na–S batteries. The cathode material exhibits extremely stable cycling performance, delivering an initial specific capacity of 392 mA h g–1 and retains 378 mA h g–1 after 500 cycles at 1C. The excellent performance is attributed to the synergistic effect of the structural encapsulation as well as chemical immobilization of polysulfides, significantly suppressing their gradual dissolution into liquid electrolyte. Density functional theory (DFT) calculations reveal that through favorable Lewis acid–base interactions, AlOOH catalyzes the redox conversion of the higher‐order polysulfides (Na2Sn, 6 ≤ n ≤ 8) to the lower‐order polysulfides (Na2Sx, 1 ≤ x ≤ 2). The importance of Lewis acid–base catalysis to enhance the overall performance of these batteries is demonstrated.

The combination of Mg and S is considered as an attractive candidate for metal-sulfur batteries due to their high volumetric energy density and adequate existence of natural resources. However, MgÀ S batteries suffer from polysulfide dissolution and shuttling which leads to reduced cycle life and stability.Here we report the significance of the chemical interaction between magnesium polysulfide and N, S dual-doped carbon cloth for improving the cycle life. Compared to undoped carbon cloth, the dual-doped carbon cloth as current collector shows improved electrochemical performance. When the dual-doped carbon cloth as current collector is used in MgÀ S cell, it retains the capacity up to 388 mAhg À 1 after 40 cycles. The mechanisms of MgÀ S battery and chemical interaction of polysulfides with dopant are investigated using X-ray photoelectron spectroscopy technique. The report clearly directs a new way to improve the performance of MgÀ S battery using a modified current collector.