Electrolytic Graphene Encapsulated CeO2 for Lithium-Sulfur Battery Interlayer Separator.

Rare earth elements and graphene composites exhibit better catalytic properties in energy storage materials. The introduction of rare earth oxide and graphene composites as functional layers into the separator to seal the "shuttle effect" formed by polysulfides during the discharge process has proven to be effective. In this study, we prepared CeO2/graphene composites (labeled as CeG) by intercalation exfoliation and in situ electrodeposition methods simultaneously, in which CeO2 was encapsulated in large folds of graphene, which exhibited good defect levels (ID/IG < 1) and its intrinsically superior physical structure acted as a shielding layer to hinder the shuttle of polysulfides, improving the cycling stability and rate of cell performance. The separator cell with CeG achieves an initial discharge specific capacity of 1133.5 mAh/g at 0.5C, excellent rate performance (978.5 mAh/g at 2C), and long cycling (790 mAh/g after 400 cycles).

Graphene/Heterojunction Composite Prepared by Carbon Thermal Reduction as a Sulfur Host for Lithium-Sulfur Batteries.

An interlayer nanocomposite (CC@rGO) consisting of a graphene heterojunction with CoO and Co9S8 was prepared using a simple and low-cost hydrothermal calcination method, which was tested as a cathode sulfur carrier for lithium-sulfur batteries. The CC@rGO composite comprises a spherical heterostructure uniformly distributed between graphene sheet layers, preventing stacking the graphene sheet layer. After the introduction of cobalt heterojunction on a graphene substrate, the Co element content increases the reactive sites of the composite and improves its electrochemical properties to some extent. The composite exhibited good cycling performance with an initial discharge capacity of 847.51 mAh/g at 0.5 C and a capacity decay rate of 0.0448% after 500 cycles, which also kept 452.91 mAh/g at 1 C and in the rate test from 3 C back to 0.1 C maintained 993.27 mAh/g. This article provides insight into the design of cathode materials for lithium-sulfur batteries.

Defining the sensitivity landscape of EGFR variants to tyrosine kinase inhibitors.

Tyrosine kinase inhibitor (TKI) is a standard treatment for patients with NSCLC harboring constitutively active epidermal growth factor receptor (EGFR) mutations. However, most rare EGFR mutations lack treatment regimens except for the well-studied ones. We constructed two EGFR variant libraries containing substitutions, deletions, or insertions using the saturation mutagenesis method. All the variants were located in the EGFR mutation hotspot (exons 18-21). The sensitivity of these variants to afatinib, erlotinib, gefitinib, icotinib, and osimertinib was systematically studied by determining their enrichment in massively parallel cytotoxicity assays using an endogenous EGFR-depleted cell line. A total of 3914 and 70,475 variants were detected in the constructed EGFR Substitution-Deletion (Sub-Del) and exon 20 Insertion (Ins) libraries. Of the 3914 Sub-Del variants, 221 proliferated fast in the control assay and were sensitive to EGFR-TKIs. For the 70,475 Ins variants, insertions at amino acid positions 770-774 were highly enriched in all 5 TKI cytotoxicity assays. Moreover, the top 5% of the enriched insertion variants included a glycine or serine insertion at high frequency. We present a comprehensive reference for the sensitivity of EGFR variants to five commonly used TKIs. The approach used here should be applicable to other genes and targeted drugs.

Effect of High-Current Pulsed Electron Beam on Properties of Graphene-Modified Aluminum Titanium Carbide Composites.

High-current pulse electron beam (HCPEB) is an advanced surface modification technology developed in recent decades. This paper focuses on the effect of 0.3 wt.% graphene on the electrical conductivity and microhardness of HCPEB-treated Al-20TiC composites. The SEM results show that the titanium carbide was uniformly distributed in the aluminum matrix of the initial sample. Conversely, the graphene showed a small aggregation, and there were holes and cracks on the top surface of the sample. After HCPEB modification, the agglomeration of graphene gradually improved, and the number of surface pores reduced. The X-ray diffraction results show that after HCPEB treatment, the aluminum diffraction peak widened and shifted to a higher angle and the grain was significantly refined. Compared with the initial Al-20TiC composite samples, the conductivity of graphene-modified HCPEB-treated sample increased by 94.3%. The microhardness test results show that the microhardness of the graphene-modified HCPEB-treated sample increased by 18.4%, compared with the initial Al-20TiC composite samples. This enhancement of microhardness is attributed to the joint effects of fine grain strengthening, dispersion strengthening of the second phase, solution strengthening and dislocation strengthening. In brief, HCPEB has good application prospects for powder metallurgy in future.

A Study on the Effect of Graphene in Enhancing the Electrochemical Properties of SnO2-Fe2O3 Anode Materials.

To enhance the conductivity and volume expansion during the charging and discharging of transition metal oxide anode materials, rGO-SnO2-Fe2O3 composite materials with different contents of rGO were prepared by the in situ hydrothermal synthesis method. The SEM morphology revealed a sphere-like fluffy structure, particles of the 0.4%rGO-10%SnO2-Fe2O3 composite were smaller and more compact with a specific surface area of 223.19 m2/g, the first discharge capacity of 1423.75 mAh/g, and the specific capacity could be maintained at 687.60 mAh/g even after 100 cycles. It exhibited a good ratio performance and electrochemical reversibility, smaller charge transfer resistance, and contact resistance, which aided in lithium-ion transport. Its superior electrochemical performance was due to the addition of graphene, which made the spherical particle size distribution more uniform, effectively lowering the volume expansion during the process of charging and discharging and improving the electrochemical cycle stability of the anode materials.

Double Heteroatom Reconfigured Polar Catalytic Surface Powers High-Performance Lithium-Sulfur Batteries.

The modification of apolar carbon materials by heteroatom doping is an effective method that can effectively improve the surface polarity of carbon materials. In the main body of the lithium-sulfur battery cathode, the structural properties of the carbon material itself with porous structure and large specific surface area provide sufficient space for sulfur accommodation and mitigate the bulk effect of the sulfur cathode (79%). The polarized surface of the reconstructed carbon material possesses strong adsorption effect on LiPs, which mitigates the notorious "shuttle effect." In this paper, the surface structure of the Ketjen black cathode body was reconstructed by B and N double heteroatoms to polarize it. The modified polarized Ketjen black improves the adsorption and anchoring ability of LiPs during the reaction and accelerates their kinetic conversion, while its own uniformly distributed small mesopores and oversized BET structural properties are beneficial to mitigate the bulk effect of sulfur cathodes. Lithium-sulfur batteries using B and N modified cathodes have an initial discharge capacity of 1344.49 mAh/g at 0.1 C and excellent cycling stability at 0.5 C (381.4 mAh/g after 100 cycles).