Nanoparticles of fast lithium-ion-conducting solid electrolyte LiAlTi(PO) (LATP) are prepared by a modified citric-acid-assisted sol-gel method that involves a two-step heat treatment in which the dry gel is calcined first in argon and then in air. The obtained LATP exhibits smaller particle size (down to 40 nm) with a narrower size distribution and less aggregation than LATP prepared by a conventional sol-gel method because of a polymeric network that preserves during LATP crystallization. It has a high relative density of 97.0% and a high room-temperature conductivity of 5.9 × 10 S cm. The as-prepared superfine LATP is further used to composite with a spinel LiMnO cathode in lithium ion batteries by simple grinding. This noncoating speckled layer over the LiMnO particle surface has a minimal effect on the electronic conductivity of the electrode while offering excellent ionic conductivity. The cycling stability and rate capability of LiMnO are greatly improved at both ambient and elevated temperatures. After 100 cycles at 25 and 55 °C, the capacity retentions are 96.0% and 89.0%, respectively, considerably higher than the values of pristine LiMnO (61.0% at 25 °C; 51.5% at 55 °C) and mechanical LiMnO composite with LATP made by a conventional sol-gel method (85.0% at 25 °C; 71.4% at 55 °C).

No abstract

No abstract

Graphene nanosheets (GSs) were prepared via liquid-phase non-covalent exfoliation of graphite powder in N,N-dimethylformamide under the assistance of copper(II) meso-tetra(4-carboxyphenyl)porphyrin tetrasodium salt Na(CuTCPP). A glassy carbon electrode (GCE) was modified with a film of such GSs which, due to the good electrical conductivity of graphene and the electrocatalytic properties of Na(CuTCPP), is capable of simultaneous determination of acetaminophen (AC) and dopamine (DA). The peak currents, best measured at voltage of 0.2 V (for DA) and 0.4 V (for AC; both vs. SCE), increase linearly in the 0.0024-3.6 μM and 0.004-7.6 μM concentration ranges, respectively. The detection limits are 0.8 nM for DA and 0.7 nM for AC. The sensor was successfully applied to the simultaneous determination of AC and DA in pharmaceutical preparations and spiked human serum. The results were in good agreement with those obtained for the same samples by HPLC. Graphical abstract Graphene nanosheets were prepared via a facile liquid-phase exfoliation of graphite with the assistance of copper(II) meso-tetra(4-carboxyphenyl)porphyrin tetrasodium salt. A graphene nanosheet-film modified glassy carbon electrode was fabricated to determine acetaminophen and dopamine through a simple and effective strategy.

A simple and practicable evaporation-induced self-assembly (EISA) method is introduced for the first time to prepare nanosized solid electrolyte Li1.4Al0.4Ti1.6(PO4)3 (LATP) for all-solid-state lithium-ion batteries. A pure Na+ super ion conductor (NASICON) phase is confirmed by X-ray diffraction (XRD) analysis, and its primary particle size is down to 70 nm by optimizing evaporation rate of the solvent. Excellent room temperature bulk and total lithium-ion conductivities of 2.09 × 10−3 S cm−1 and 3.63 × 10−4 S cm−1 are obtained, with an ion-hopping activation energy as low as 0.286 eV.