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Solid‐state Li metal batteries (SSLMBs) are attractive due to their capability to simultaneously offer high energy density and high‐level safety when combining Li metal anodes, solid‐state electrolytes (SSEs), and high‐voltage cathodes together. However, SSLMBs may well incur short circuits caused by Li dendrites penetrations, which mainly originate from the instability and poor contact between Li metal and SSEs. Herein, by taking full advantage of the reaction products of Li and Li1.3Al0.3Ti1.7(PO4)3 (LATP), a lithium‐LATP composite anode (Li‐LATP) is obtained, in which a stable matrix is formed to enhance the contact between Li and the garnet‐type SSEs, alleviating the volume change and preserving an intact interface during the charge/discharge process. Consequently, the Li‐LATP/garnet/Li‐LATP symmetric cell displays a fairly low interfacial resistance of 6 Ω cm2 and stable cycling performance for over 2500 h with a low overpotential. Furthermore, the LiCoO2/garnet/Li‐LATP full cell also shows a high discharge capacity of 159 mAh g−1 and great cycling performance. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) fibers are more suitable than films for portable or wearable devices. Herein, 2–3 nm thick poly (3,4‐ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) layer‐coated tellurium nanowires (PC‐Te NWs) are in situ prepared by a hydrothermal method. Then a series of PEDOT: PSS/PC‐Te NWs composite fibers are prepared by wet spinning and post‐treatment. The nanolayer prevents the agglomeration of the Te NWs and makes the NWs and PEDOT:PSS matrix have good compatibility, which results in the PC‐Te NWs content to a high value of 70 wt% and the fibers still with flexibility. The high aspect ratio of the PC‐Te NWs and the stress from the inner wall of the needle during spinning make the NWs ordered align along the composite fiber. Due to the large content and orientational arrangement of the PC‐Te NWs, as well as effective post‐treatment, an optimized composite fiber shows a power factor of 385.4 µW m−1 K−2 at 300 K, which is ≈4.9 times as high as the highest value of previously reported PEDOT:PSS/Te NWs‐based composite fibers. In addition, the composite fiber has good flexibility. The flexible TE generators assembled have excellent output performance. This work provides an effective strategy for the preparation of high‐performance flexible TE composite fibers. [ABSTRACT FROM AUTHOR]

Solid electrolytes are pivotal in ushering in the new era of energy technology, offering fresh prospects for its advancement. Recently, halide solid electrolytes have garnered significant attention due to their wide electrochemical window, high lithium ion conductivity at room temperature (RT), and high stability to the positive electrode. In particular, a promising LaCl3-based solid-state electrolyte (SSE) with a non-close-packed structure could provide abundant one-dimensional (1D) channels for lithium ions, and it is compatible with lithium metal. However, the 1D channels are easily blocked by defects, and doping with several high-cost elements on the La site has been reported to optimize the migration path. Therefore, there is an imperative need to devise innovative strategies to further enhance the properties of LaCl3-based SSEs and to expand the LaCl3-based material family. Here, we report a cost-effective Zr4+ and O2− co-doping LaCl3-based oxychloride Li+ superionic conductor (Li0.5+xZr0.25La0.5Cl3−xOx). The sample with the optimized composition, Li0.8Zr0.25La0.5Cl2.7O0.3, exhibits a high ionic conductivity of 0.75 mS cm−1 at room temperature, a low activation energy of 0.23 eV, and remarkable compatibility with Li metal. The critical current density attains a high value of 7 mA cm−2, and the long-term cycling of Li–Li symmetric cells experiences the stable plating/striping process under 0.1 mA cm−2 and 3 mA cm−2. Furthermore, the all-solid-state battery with the LiCoO2 composite cathode delivers commendable cycling performance at 0.2C and 0.5C. [ABSTRACT FROM AUTHOR]

In this work, flexible Cu2−xS films on nylon membranes are prepared by combining a simple hydrothermal synthesis and vacuum filtration followed by hot pressing. The films consist of Cu2S and Cu1.96S two phases with grain sizes from nano to submicron. Doping Se on the S site not only increases the Cu1.96S content in the Cu2−xS to increase carrier concentration but also modifies electronic structure, thereby greatly improves the electrical properties of the Cu2−xS. Specifically, an optimal composite film with a nominal composition of Cu2−xS0.98Se0.02 exhibits a high power factor of ~150.1 μW m−1 K−2 at 300 K, which increases by ~138% compared to that of the pristine Cu2−xS film. Meanwhile, the composite film shows outstanding flexibility (~97.2% of the original electrical conductivity is maintained after 1500 bending cycles with a bending radius of 4 mm). A four-leg flexible thermoelectric (TE) generator assembled with the optimal film generates a maximum power of 329.6 nW (corresponding power density of 1.70 W m−2) at a temperature difference of 31.1 K. This work provides a simple route to the preparation of high TE performance Cu2−xS-based films. [ABSTRACT FROM AUTHOR]