In situ Gel Electrolytes for the Interfacial Regulation of Lithium Metal Batteries.

With the popularity and development of electronic devices, the demand for lithium batteries is increasing, which also puts high demands on the energy density, cycle life and safety of lithium batteries. Gel electrolytes achieve both of these requirements by curing the electrolytes to reduce the interfacial side reactions of lithium metal batteries. The ionic conductivity of the gel electrolytes prepared by in situ curing reach 8.0×10-4  S cm-1 , and the ionic mobility number is 0.53. Meanwhile, the gel electrolytes maintain a stable electrochemical window of 1.0-5.0 V. Benefited with the interfacial regulation of PEGDA gel electrolytes, the gel lithium metal batteries show better cycling stability, and achieved 97 % capacity retention after 200 cycles (0.2 C) with a lower increasing rate of impedance.

3D Vertically Aligned Microchannel Three-Layer All Ceramic Lithium Ion Battery for High-Rate and Long-Cycle Electrochemical Energy Storage.

Due to the growing energy and safety demands, rechargeable all-solid-state Li+ batteries using metallic Li anode and ceramic-based electrolytes have attracted extensive attentions. However, the inherent safety problem of Li metal anode, the ceramic-electrode low Li+ conductivity, and the high electrolyte/electrode solid-solid interfacial impedance slow the development of high-performance all-solid-state batteries. In this work, a three-layer all ceramic battery with Li4 Ti5 O12 ceramic as anode, LiCoO2 as cathode, and Li0.34 La0.56 TiO3 as electrolyte to solve the safety problem is proposed. The low Li+ conductivity of electrodes are effectively addressed by fabricating the electrode/electrolyte composite electrodes in 3D vertically aligned microchannel structures. The large interfacial impedance is greatly reduced by co-constructing the microchannel-dense-microchannel structure with high Li+ conducting electrolytes. Experimental results reveal that a working cell by applying the 3D vertically aligned microchannel three-layer all ceramic structure enables high energy storage at 2 C rate and long cycling stability for more than 500 times.

Regulating Ni3+ contents by a cobalt doping strategy in ternary NixCo3-xAl1-LDH nanoflowers for high-performance charge storage.

NiAl-LDH and CoAl-LDH as typical two-dimensional layered materials have been widely used as supercapacitor cathodes due to their special composition, morphology and rich electrochemically active centers. However, a clear strategy to enhance their electrochemical performances remains lacking. Here, with NixCo3-xAl1-LDHs (x = 1, 1.5 and 2, in short: NiCoAl-LDHs) as examples, a Co/Ni ion co-incorporation strategy was used to study the possible effects on their capacitive performance. Our work demonstrated that different cobalt contents in NiCoAl-LDHs show no obvious changes in their crystal structure, morphology, surface area, etc. However, incorporating more cobalt ions into NiCoAl-LDHs will generate more oxygen vacancies, causing more Ni3+ ions to appear on the surface, and higher concentrations of Ni3+ ions and more oxygen vacancies play active roles in enhancing the capacitive performances. The Ni1Co2Al1-LDH electrode with a Ni3+/Ni2+ ratio of 1.44 and an oxygen vacancy concentration of 54.83% delivers a high specific capacitance (728 C g-1 at 1 A g-1) and excellent capacitance retention (93.18% of initial capacitance at 30 A g-1 after 10 000 cycles).

Medium-Entropy SrV1/3Fe1/3Mo1/3O3 with High Conductivity and Strong Stability as SOFCs High-Performance Anode.

Perovskite oxides using solid oxide fuel cells (SOFCs) anodes should possess high chemical stability, adequate electronic conductivity and excellent catalytic oxidation for fuel gas. In this work, the medium-entropy SrV1/3Fe1/3Mo1/3O3 (SVFMO) with Fe, V and Mo co-existing in the B site of a perovskite structure was fabricated in reducing 5% H2/Ar mixed gas: (1) SVFMO demonstrates more stable physicochemical properties when using SOFCs anodes in a reducing environment; (2) the co-existence of Fe, V and Mo in SVFMO forms more small-polaron couples, demonstrating greatly enhanced electronic conductivity. With SVFMO in a porous structure (simulating the porous anode layer), its electronic conductivity can also reach 70 S cm-1 when testing at 800 °C in an H2 atmosphere; (3) SVFMO with more oxygen vacancies achieves higher catalytic ability for fuel gas, as an SOFCs anode layer demonstrates 720 mW cm-2 at 850 °C.