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Silicon is widely recognized as an ideal anode material due to its high specific capacity, low lithiation potential, high abundance, and environmental friendliness. Nevertheless, the immense volume expansion during the lithiation leads to pulverization of silicon particles, which causes electrode failure with a rapid capacity decay. Herein, the polymerized 1, 3‐dioxolane (PDOL) electrolyte is used to stabilize the micro‐silicon Si anode via in situ polymerization route. The conformality of the quasi‐solid electrolyte suppresses the pulverization of the Si microparticles (SiMPs) effectively and thus alleviates the capacity decay. The SiMPs/PDOL anode shows an excellent initial CE of 97.5% and maintains a reversible capacity of 1837.1 mAh g−1 at 500 mA g−1 after 100 cycles. The Si/PDOL/LiFePO4 full cells also exhibit a stable cycling performance with a capacity retention of 76.3% after 300 cycles. This work provides a new and easy path for the practical application of silicon anode at low cost. [ABSTRACT FROM AUTHOR]

Li‐rich Mn‐based layered oxides (LRLOs) with ultrahigh specific capacities are promising cathode materials for high energy density lithium‐ion batteries. Nevertheless, severe irreversible oxygen release, structure degradation, capacity and voltage attenuation hinder their commercialization due to the uncontrollable oxygen redox chemistry originated from unhybridized O 2p orbitals. Herein, a strategy to generate bulk oxygen vacancies is proposed. And bulk oxygen vacancies are constructed by lowering the formation energy of oxygen vacancies in LRLOs via Gd‐doping. The energy level and the amount of unhybridized O 2p states are reduced to partly inhibit the oxygen redox activity. Surprisingly, the oxygen redox is not fully activated in the first cycle and is further activated in the second cycle. Moreover, the reduced oxygen redox activity significantly suppresses the oxygen release, lattice volume change, layered‐to‐spinel phase transition. As a result, the amount of oxygen gas release is reduced from 98.80 to ≈0 nmol mg−1 in the first cycle. Superior cycle stability of 90.4% capacity retention after 300 cycles and small voltage decay of only 1.013 mV per cycle are achieved. This study provides a valuable bulk oxygen vacancies strategy to regulate the unhybridized O 2p orbitals for designing high‐performance Li‐rich Mn‐based layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

Lithium–sulfur/selenium batteries have attracted broad interest and achieved good performance using ether‐based electrolytes. However, when the ether‐based electrolytes are employed, Li–S/Se battery systems still have several inevitable drawbacks inhibiting their practical applications, such as intermediate product dissolution issues, and a dependency on a high content of electrolyte. Thus, it is urgent to pay attention to the electrochemical properties of SexSy cathodes in carbonate‐based electrolytes, which may avoid the above mentioned problems. In this work, a series of mesoporous carbon/SexSy (CMK‐3/SexSy) composites with covalent Se‐S bonds and different Se/S molar ratios are prepared and their working mechanism in carbonate‐based electrolytes is systematically investigated by combining experimental analysis and theoretical calculations. This work finds that the Se in the CMK‐3/SexSy cathode is beneficial for the transportation of Li+ ions and forms a thin cathode electrolyte interphase (CEI) during the discharge–charge process. Furthermore, S substitution in Se8 molecules can enhance the specific capacity and lower the bond breaking and lithiation energies. The optimal CMK‐3/SexSy cathode delivers outstanding performance with a high reversible capacity of 609 mA h g−1 at 1 A g−1 over 300 cycles. [ABSTRACT FROM AUTHOR]

The well‐known "shuttle effect" of the intermediate lithium polysulfides (LiPSs) and low sulfur utilization hinder the practical application of lithium–sulfur (Li–S) batteries. Herein, we describe a novel C60–S supramolecular complex with high‐density active sites for LiPS adsorption that was formed by a simple one‐step process as a cathode material for Li–S batteries. Benefiting from the cocrystal structure, 100 % of the C60 molecules in the complex can offer active sites to adsorb LiPSs and catalyze their conversion. Furthermore, the lithiated C60 cores promote internal ion transport inside the composite cathode. At a low electrolyte/sulfur ratio of 5 μL mg−1, the C60–S cathode with a sulfur loading of 4 mg cm−2 exhibited a high capacity of 809 mAh g−1 (3.2 mAh cm−2). The development of the C60–S supramolecular complex will inspire the invention of a new family of S/fullerenes as cathodes for high‐performance Li–S batteries and extend the application of fullerenes. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are promising next‐generation rechargeable batteries due to thier high energy density, low cost, and environmental friendliness. However, the extremely low electrical conductivity of sulfur and the dissolution of polysulfides limit their actual electrochemical performances, especially in the case of high sulfur mass loading. Here, a new strategy based on intrinsic point defects of materials is proposed to simultaneously enhance the electrical conductivity of active material and regulate the migration of polysulfides. Taking advantage of ultrathin and lightweight Bi2Te2.7Se0.3 (BTS) interlayers with high‐density antisite defects on the separator surface, the Li–S battery with BTS interlayer shows a capacity of 756 mAh g−1 at 2C and a low capacity decay rate of 0.1% over 300 cycles. The BTS interlayer can not only enhance the active material utilization but also improve capacity retention. The defect engineering strategy accompanied with facile method is promising for the development of advanced Li–S batteries for practical application. [ABSTRACT FROM AUTHOR]

Using a solid‐state electrolyte (SSE) to stabilize the Li metal anode is widely considered a promising route to develop next‐generation high energy density lithium batteries. Here, a new polycrystalline aluminate‐based SSE (named Li–Al–O SSE) with good capability is introduced to protect Li metal. The SSE is formed on the Li metal surface via a chemical reaction between LiOH and triethylaluminum (TEAL) with the existence of LiTFSI‐based electrolyte. It is a continuous film that consists of polycrystalline LiAlO2, Li3AlO3, Al2O3, Li2CO3, LiF, and some organic compounds. Such Li–Al–O SSE possesses a room‐temperature ionic conductivity as high as 1.42 × 10−4 S cm−1. Meanwhile, it effectively protects the Li anode from the corrosion of H2O, O2, and organic solvent, and suppresses the growth of Li dendrite. With the protection of the Li–Al–O SSE, the cycle life of Li|Li symmetric cell and Li|O2 cell is substantially elongated, indicating that the SSE exhibits an excellent protective effect under both inert and oxidizing circumstances. [ABSTRACT FROM AUTHOR]

Superionic halides have attracted widespread attention as solid electrolytes due to their excellent ionic conductivity, soft texture, and stability toward high-voltage electrode materials. Among them, Li 3 InCl 6 has aroused interest since it can be easily synthesized in water or ethanol. However, investigations into the influence of solvents on both the crystal structure and properties remain unexplored. In this work, Li 3 InCl 6 is synthesized by three different solvents: water, ethanol, and water-ethanol mixture, and the difference in properties has been studied. The results show that the product obtained by the ethanol solvent demonstrates the largest unit cell parameters with more vacancies, which tend to crystallize on the (131) plane and provide the 3D isotropic network migration for lithium-ions. Thus, it exhibits the highest ionic conductivity (1.06 mS cm -1 ) at room temperature and the lowest binding energy (0.272 eV). The assembled all-solid-state lithium metal batteries (ASSLMBs) employing Li 3 InCl 6 electrolytes demonstrate a high initial discharge capacity of 153.9 mA h g -1 at 0.1 C (1 C = 170 mA h g -1 ) and the reversible capacity retention rate can reach 82.83% after 50 cycles. This work studies the difference in ionic conductivity between Li 3 InCl 6 electrolytes synthesized by different solvents, which can provide a reference for the future synthesis of halide electrolytes and enable their practical application in halide-based ASSLMBs with a high energy density.

Room-temperature sodium-sulfur (RT-Na/S) batteries hold great promise to meet the requirements of large-scale energy storage due to their high theoretical energy density, low material cost, resource abundance, and environmental benignity. However, the poor cycle performance and low utilization of active sulfur greatly hinder their practical application. As the essential part directly related to the battery performance, the S-based cathode has attracted tremendous research interests in recent years. This review highlights recent progress in cathode materials for RT-Na/S batteries. Particularly, basic insights into the Na/S reaction mechanism are presented and representative works on S-based cathode materials are systematically summarized. The remaining challenges and developing trends of RT-Na/S batteries are also discussed. We hope this review can shed light on the field of next-generation metal-sulfur batteries., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)