RESUMO
Tunnel-type NaGe3/2Mn1/2O4 was fabricated for anode of sodium ion batteries, delivering a discharge capacity of 200.32 mAh g-1 and an ultra-low potential platform compared with that of pure Na4Ge9O20 (NGO). The results of X-ray photoelectron spectroscopy (XPS) demonstrate that Ge redox occurs, and partial substitution of Mn effectively improves the Na-storage properties compared to those of NGO.
RESUMO
The major obstacles which prohibit the practical applications of alloy-type anodes include insufficient ionic/electronic transportations and structural failures. Herein, we report the fabrication of a carbon-coated nanoporous SnSb alloy (NP-SnOxSb@C) and its application as an anode in Li-ion batteries (LIBs). The as-fabricated NP-SnOxSb@C is characterized by SEM and TEM and demonstrates a bi-continuous nanoporous structure. Amorphous carbon is found to be uniformly coated on the alloy surface. When used as an anode for LIB, NP-SnOxSb@C displays a high capacity (850 mA h g-1 after the 50th cycle) and good rate performance of 664 mA h g-1 at 2000 mA g-1. The improved electrochemical performance is mainly due to a high Li+ diffusion coefficient and low charge transfer resistance between the nanoporous structure and conductive carbon layer. The facile material fabrication process and good electrochemical performance enable the practical utilization of this anode for high-performance LIBs.
RESUMO
Plants of Paeonia are valuable for their ornamental and medicinal values. Genetic relations and hybrids identification among different sections of Paeonia were studied using sequence related amplified polymorphism (SRAP) markers. A total of 29 cultivars including 2 intersectional hybrids, 13 sect. Moutan and 14 from sect. Paeonia were used. A total of 197 bands were produced using 24 primer combinations, among which 187 bands showed polymorphism. From the bands amplified, we can identify the peony cultivars using unique SRAP markers and specific primer combinations. Fourteen peony cultivars were distinguished among each other by using totally 35 SRAP markers, which were generated by 16 primer pairs. Two specific primer pairs of Me8/Em8 and Me8/Em1 can be used to identify cultivars from different sections. The mean genetic similarity coefficient (GS), the gene diversity (GD), and the Shannon's information index of peony cultivars were 0.45, 0.19 and 0.32, respectively. Both UPGMA (unweighted pair-group method of arithmetic average) dendrogram and PCA (principle component analysis) analysis showed clear genetic relationships among the 29 peony cultivars, and within section and its intersectional hybrids. The above results are valuable for estimating and analyzing genetic background of Paeonia, parent selection in crossing breeding programs, molecular marker assisted selection (MAS) breeding for further germplasm innovation programs.