In-Situ Intermolecular Interaction in Composite Polymer Electrolyte for Ultralong Life Quasi-Solid-State Lithium Metal Batteries.

Solid-state lithium metal batteries built with composite polymer electrolytes using cubic garnets as active fillers are particularly attractive owing to their high energy density, easy manufacturing and inherent safety. However, the uncontrollable formation of intractable contaminant on garnet surface usually aggravates poor interfacial contact with polymer matrix and deteriorates Li+ pathways. Here we report a rational designed intermolecular interaction in composite electrolytes that utilizing contaminants as reaction initiator to generate Li+ conducting ether oligomers, which further emerge as molecular cross-linkers between inorganic fillers and polymer matrix, creating dense and homogeneous interfacial Li+ immigration channels in the composite electrolytes. The delicate design results in a remarkable ionic conductivity of 1.43×10-3  S cm-1 and an unprecedented 1000 cycles with 90 % capacity retention at room temperature is achieved for the assembled solid-state batteries.

Versatile Strategy for Realizing Flexible Room-Temperature All-Solid-State Battery through a Synergistic Combination of Salt Affluent PEO and Li6.75La3Zr1.75Ta0.25O12 Nanofibers.

All-solid-state lithium metal batteries are highly attractive because of their high energy density and inherent safety. However, it is still a great challenge to design the solid electrolytes with high ionic conductivity at room temperature and good electrode/electrolyte interfacial compatibility simultaneously in a facile and scalable way. In this work, for the first time, the combination of salt affluent Poly(ethylene oxide) with Li6.75La3Zr1.75Ta0.25O12 nanofibers was designed and intensively evaluated. The synergistic effect of each component in the electrolyte enhances the ionic conductivity to 2.13 × 10-4 S cm-1 at 25 °C and exhibits a high transference number of 0.57. The composite electrolyte possesses superior interfacial stability against Li metal for over 680 h in Li symmetric cells even at a relatively high current density of 2 mA cm-2. The all-solid-state batteries employing the solid electrolytes exhibit excellent cycling stability at room temperature and superior safety performance. This work proposes a brand-new strategy to design and fabricate solid electrolytes in a versatile way for room-temperature all-solid-state batteries.

Bottom-up synthesis of iron and nitrogen dual-doped porous carbon nanosheets for efficient oxygen reduction.

Iron and nitrogen co-doped porous carbon nanosheets (Fe,N-PCNs) with a small thickness, smooth surface and high specific surface area are fabricated by a facile bottom-up approach as highly efficient noble metal-free catalysts for the oxygen reduction reaction (ORR). The Fe,N-PCN catalyst exhibits a positive half-wave potential (E1/2) (0.87 V vs. RHE), a similar four-electron pathway in 0.1 M KOH medium, and an excellent long-term stability.

Tailored high cycling performance in a solid polymer electrolyte with perovskite-type Li0.33La0.557TiO3 nanofibers for all-solid-state lithium ion batteries.

Solid polymer electrolytes (SPEs) have drawn considerable attention owing to their reliable safety performance, electrochemical stability and exceptional flexibility, which make them superior to conventional liquid electrolytes. Here, we report a novel composite electrolyte which is composed of homogeneously dispersed Li ion-conducting Li0.33La0.557TiO3 (LLTO) nanowires in a poly(ethylene oxide) (PEO)/LiClO4 matrix. It is demonstrated that only 3 wt% LLTO nanofibers are needed for the optimal performance of SPEs. The PEO-based composite electrolyte shows an excellent Li ion conductivity of 4.01 × 10-4 S cm-1 at 60 °C. In addition, it is worth mentioning that the all-solid-state lithium battery based on this composite electrolyte exhibits a specific capacity of 140 mA h g-1 and an excellent capacity retention of 92.4% after running 100 cycles at a rate of 1C and 60 °C. The study offers a superior alternative for the design of PEO-based solid composite electrolytes.