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However, the shuttle effect triggered by the dissolution of long-chain polysulfides (Li 2 S x , 4 ≤ x ≤ 8) results in severe active sulfur loss and fast capacity decay, which severely hinders the commercial application of these batteries. [4,6] Fundamentally, these problems are a result of the slow and complex sulfur reduction reaction (SRR), i.e., the sluggish kinetic transformation of soluble lithium polysulfides (LiPSs) to insoluble Li 2 S 2 /Li 2 S (discharge products). [7,8] Therefore, exploring effective strategies to accelerate the conversion of LiPSs from the liquid to the solid state is essential to boost the practical energy density and lifespan of lithium-sulfur batteries. [9,10] Considerable efforts have been devoted to addressing the aforementioned problems, typically by using sulfides, nitrides, phosphides as host materials to trap the LiPSs in the sulfur cathode. [11][12][13][14] However, these physical or electrostatic confinement/trapping methods fail to entirely avoid the dissolution and accumulation of LiPSs in the electrolyte. [8] A catalytic approach has therefore been proposed as a more proactive solution to cure the shuttle effect by accelerating the conversion of the liquid-phase long-chain LiPSs into final solid-phase discharge products. [15,16] Like the oxygen Seeking an electrochemical catalyst to accelerate the liquid-to-solid conversion of soluble lithium polysulfides to insoluble products is crucial to inhibit the shuttle effect in lithium-sulfur (Li-S) batteries and thus increase their practical energy density. Mn-based mullite (SmMn 2 O 5 ) is used as a model catalyst for the sulfur redox reaction to show how the design rules involving lattice matching and 3d-orbital selection improve catalyst performance. Theoretical simulation shows that the positions of Mn and O active sites on the (001) surface are a good match with those of Li and S atoms in polysulfides, resulting in their tight anchoring to each other. Fundamentally, dz 2 and dx 2 −y 2 around the Fermi level are found to be crucial for strongly coupling with the p-orbitals of the polysulfides and thus decreasing the redox overpotential. Following the theoretical calculation, SmMn 2 O 5 catalyst is synthesized and used as an interlayer in a Li-S battery. The resulted battery has a high cycling stability over 1500 cycles at 0.5 C and more promisingly a high areal capacity of 7.5 mAh cm −2 is achieved with a sulfur loading of ≈5.6 mg cm −2 under the condition of a low electrolyte/sulfur (E/S) value ≈4.6 µL mg −1 .

A novel amphiphilic diblock copolymer composed of a hydrophilic poly(ethylene oxide) block and a hydrophobic block copolymerized by azobenzene-containing methacrylate and N-isopropylacrylamide was synthesized using ATRP. The polymer micelles showed dual responsiveness to heat and light. The size of the micelles was dependent on temperature and the encapsulated substance in the hydrophobic cores was released during heating and cooling processes. The hydrophobicity of the micellar cores appeared as a reversible change in response to light with neither disruption of the micelles nor leakage of the encapsulated substance while H-aggregation of the azobenzene moieties was detected.

A novel amphiphilic diblock copolymer composed of a hydrophilic poly(ethylene oxide) and a hydrophobic polymethacrylate with photochromic azopyridine moieties in the side groups was synthesized by atom transfer radical polymerization. The copolymeric vesicles showed photoinduced circular process including fusion, damage and defect formation, disruption, disintegration and rearrangement in H(2) O/THF during the irradiation of UV light. The process of photoresponsive cycle can be inhibited at any moment by visible light.

Inferior cycling stability at elevated temperature is a big challenge for the commercial application of nickel-rich cathode materials because more serious phase transition, transition metal ion dissolution and side reaction of interface happen at elevated temperature than at room temperature. In the present work, strategies of element doping and surface coating are utilized together to stabilize the structure and interface electrochemistry. We successfully synthesized a Zr-doped and LiAlO 2 -Al 2 O 3 coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 material by a simple ball milling and wet chemical method. Owing to the synergistic effect of Zr doping and dual LiAlO 2 -Al 2 O 3 coating, when cycled at 50°C, the modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 sample exhibited significantly improved cycling stability with a capacity retention of over 96.8% after 60 cycles at a current rate of 1C, while the pristine sample could only retain a capacity of 73.3%. This improved electrochemical performance can be attributed to the effective doping and coating technique employed to the LiNi 0.8 Co 0.1 Mn 0.1 O 2 sample. The Zr doping is beneficial to reduce cation mixing and suppress the phase transition, while the LiAlO 2 -Al 2 O 3 coating helps to enhance the protection of the electrode/electrolyte interface and reduce the transition metal ion dissolution.