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Inverted polymer solar cells of the conventional poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C61butyric acid methyl ester (PCBM) blend on indium tin oxide substrates were fabricated. By using mixed-solvent dispersed ZnO nanoparticles (NPs) as cathode buffer layer, device performances are improved obviously. ZnO NPs with a size of 3-5 nm synthesized by solvothermal synthesis at 65 °C show relatively wide photoluminescence peak of 300-650 nm. Based on Hansen solubility parameter theory, a mathematical method was applied to calculate the Hansen solubility parameters of bi-solvent system to disperse ZnO NPs and the proportion of each component in the mixed solvent. This excellent dispersion for ZnO NPs in the bi-solvent system has a important influence on the performance of the device. Compared to other methods of ZnO nanofilm fabrication, this method reveals a simple, convenient, moderate and effective way to manufacture the favorable buffer layer in organic solar cells. [ABSTRACT FROM AUTHOR]

Material Nano-genesis has gradually obtained more technical feedback and support in the study of lithium batteries, but problems such as volume expansion still need in-depth study. In this paper, SnO 2 –TiO 2 –CNS ternary composites were prepared by hydrothermal method and ball milling. Depending on the layered structure, the SnO 2 –TiO 2 nanoparticles are uniformly attached to carbon nanosheets. It is noteworthy that the volume variation of SnO 2 was alleviated by mixed TiO 2 and CNS, thus generating a wider space to move around for the lithium ion during the conduction process. The STC was tested for 100 cycles at 0.2 Ag-1 and the capacity was achieved 1046.1 mAhg−1. At 1.0 Ag-1, the capacity of STC can attain 1443.3 mAhg−1 after 1000 cycles. Then, the SEM image of the recovered electrode material was measured, and it was observed that the SnO 2 –TiO 2 –CNS composite remained stable. [ABSTRACT FROM AUTHOR]

• SnO 2 -Ti 2 C-C composite has been synthesized by hydrothermal and balling methods. • The ultrathin graphite nanosheet structure can facilitate lithium-ion transport. • Carbon coating can protect Ti 2 C from oxidation and self-stack. • The ternary SnO 2 -Ti 2 C-C composite can withstand high stress during cycling. • SnO 2 -Ti 2 C-C composite shows high rate and cycling stability. [Display omitted] A SnO 2 -Ti 2 C-C nanoparticle composite anode was synthesized by using facile ball milling combined with hydrothermal treatment. The SnO 2 -Ti 2 C nanoparticles were homogeneously coated with graphite nanosheets by ball milling. Graphite nanosheets served as ideal volume expansion buffers and good electron conductors. Consequently, a high initial coulombic efficiency of 80.3% was displayed, and the system exhibited a high reversible capacity of 1036.87 mAh g−1 maintained after 200 cycles at 0.2 A g−1, a rate capacity of 447.58 mAh g−1 at a high current density of 5.0 A g−1, and long cycling stability with a capacity of 763.18 mAh g−1 after 500 cycles at 2.0 A g−1. These results indicate that the incorporation of Ti 2 C, graphite nanosheets, and SnO 2 enhanced the performance of SnO 2 -based anodes for battery applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bimetallic alloy nanoparticles enhance the cycling stability during K intercalation/de-intercalation process. • A novel preparation of PIB anode via a scalable bimetallic alloy nanoparticles and carbonization. • The doped N and O elements increase the contact sites between the electrode materials and electrolyte. • The composite material has bimetallic alloy active site and conductive carbon frame. Metal-organic frameworks (MOFs) have great potential as anode materials for potassium-ion batteries (PIBs) due to their hierarchical porous structures, large number of reaction sites, and adjustable chemistry. However, the larger size of potassium ions adversely impacts the electrochemical performance and specific capacity. Therefore, it is imperative to develop novel electrode materials featuring distinctive structures for PIBs. This study achieved bimetal introduction by adding Ammonium ferric citrate during ZIF-67 growth. The resulting metal–organic skeleton of the bimetallic alloy nanoparticle (FeCo@PAZ-C) exhibits a core–shell structure and adorned with numerous microspheres on its surface, thereby offering an abundance of active sites for K+ storage. This architecture effectively reduces the diffusion path length for potassium ions and enhances electron transport pathways, ultimately contributing to improved performance. At 100 mA g−1 and after 500 cycles, the FeCo@PAZ-C electrode material demonstrated a stable specific capacity of 328 mAh/g with 95 % capacity retention. This self-sacrificing template method for MOFs offers a new approach to developing high-capacity and cycling-stable potassium-ion battery materials, broadening their potential applications. [ABSTRACT FROM AUTHOR]

SnO 2 –ZrO 2 composite nanoparticles were embedded in the few-walled carbon nanotubes (FWCNTs) network to synthesise a ternary SnO 2 –ZrO 2 -CNT nanocomposite by the hydrothermal and ball milling methods. The SnO 2 –ZrO 2 composite was uniformly dispersed in the CNT matrix. The CNTs in the composite alleviated the volume expansion during cycling, improved conductivity, and shortened the transmission path of electrons and Li+. Therefore, the SnO 2 –ZrO 2 -CNT composite showed high reversible capacity of 1072.2 mAhg−1 after 200 cycles at 0.2 Ag-1 with high initial coulomb efficiency of 77.9% and >98.8% in the following cycles, high-rate capacity of 653.6 mAhg−1 at 5.0 Ag-1, and long-term capacity of 610.7 mAhg−1 at 5.0 Ag-1 after 1000 cycles. Because of its outstanding properties, the SnO 2 –ZrO 2 -CNT nanocomposite is a promising anode material for next-generation lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized as anode materials for potassium ion batteries (KIBs) using modified Hummers, freeze drying, and thermal reduction in this paper. Layered Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized by in-situ formation of rGO and TiO 2 nanoparticles between Ti 3 C 2 layers. As one of the most important members of MXenes family, Ti 3 C 2 exhibits unique electronic characteristics, high specific surface area, strong electrical conductivity and chemically active surface, which can enhance electrode capacity. There are three ways to increase electrode conductivity and capacity: Firstly, rGO is applied as the substrate for the inlaying of TiO 2 and Ti 3 C 2 nanoparticles and nanosheets. Secondly, rGO may also buffer electrode volume changes during charging and discharging processes. In addition, the enormous surface area of rGO makes Ti 3 C 2 and TiO 2 nanoparticles dispersion well, and Ti 3 C 2 and TiO 2 nanoparticles can well separate rGO nanoparticles and prevent them from stacking up again. The synergistic effect of the three can efficiently relieve the stress and provide a rapid transport pathway between electrons and ions. The flake structure of Ti 3 C 2 /TiO 2 /rGO is advantageous to the stability of SEI film, which makes the material maintain good activity during charge and discharge process, and significantly increases its electrochemical performance. Therefore, Ti 3 C 2 /TiO 2 /rGO electrode has a high reversible capacity of 349.2 mAhg−1 after 200 cycles of 100 mAg−1 current, and a high stable capacity of 229.3 mAhg−1 after 500 cycles of 500 mAg−1 current, and has exceptional rate performance. The structure of Ti 3 C 2 /TiO 2 /rGO composite remains stable after 500 cycles, and no agglomeration occurs. The detailed reaction mechanism of Ti 3 C 2 /TiO 2 /rGO electrode as KIBs anode was analyzed by SEM, XRD, Raman, TGA, FT-IR, BET, TEM, XPS, EDS, CV, EX-situ XRD, ex-situ TEM, and so on. Therefore, it can be concluded that the Ti 3 C 2 /TiO 2 /rGO composite is an appropriate anode material for KIBs. [Display omitted] • Ti 3 C 2 /TiO 2 /rGO nanosheets were synthesized using modified Hummers, freeze drying, and thermal reduction. • The flake structure of Ti 3 C 2 /TiO 2 /rGO is advantageous to the stability of SEI film, which makes the material maintain good activity. • RGO acts as a substrate for TiO 2 and Ti 3 C 2 nanoparticles to buffer the volume change of the electrode during the charging and discharging process. • The synergistic effect of Ti 3 C 2 , TiO 2 , and rGO can efficiently relieve the stress and provide a rapid transport pathway between electrons and ions. • Ti 3 C 2 /TiO 2 /rGO electrode has a high reversible capacity of 349.2 mAhg−1 after 200 cycles of 100 mAg−1 , and 229.3 mAhg−1 after 500 cycles of 500 mAg−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary SnO 2 -ZnO-C composite has been synthesized by hydrothermal and balling methods. • The ultrathin graphite nanosheet structure can facilitate lithium-ion transport. • ZnO can withstand high stress during cycling and stabilize the structure. • The ternary SnO 2 -ZnO-C composite can withstand high stress during cycling. • Ternary SnO 2 -ZnO-C composite shows high rate and cycling stability. SnO 2 -ZnO nanoparticles were wrapped in the ultrathin graphite network to synthesize SnO 2 -ZnO-C nanocomposite by the hydrothermal and ball milling methods. The SnO 2 -ZnO hybrid was uniformly dispersed in the graphite matrix. The ultrathin graphite in the composite alleviated the volume expansion during cycling, improved conductivity and shortened the transmission path of electrons and Li+. Therefore, the SnO 2 -ZnO-C composite shows intense invertible capacity of 1192.2 mAhg−1 after 300 cycles at 0.2 Ag−1 with high initial coulomb efficiency of 78.5% and stabilizes above 99.0% after four cycles, high-rate capacity of 723.6 mAhg−1 at 5.0 Ag−1, and long-term capacity of 596.3 mAhg−1 at 5.0 Ag−1 after 1000 cycles. Thanks to its outstanding properties, the SnO 2 -ZnO-C nanocomposite is a prospective anode material for next-generation lithium-ion batteries. [ABSTRACT FROM AUTHOR]