Retarding the capacity fading and voltage decay of Li-rich Mn-based cathode materials via a compatible layer coating for high-performance lithium-ion batteries.

Li-rich Mn-based layered oxides have been considered as the most promising cathode candidate for high energy density lithium ion batteries. However, the practical application of Li-rich Mn-based layered oxides is hindered due to the capacity fading and voltage decay accompanied with structure transition from the layered structure to spinel phase during cycling. Herein, a facile surface structure repair via Ce modification is reported. The structural analysis of the bulk and coating layer was carried out using XRD, XPS, SEM and TEM, which confirmed the successful doping of Ce and formation of a Li2CeO3 coating on the surface. The modified sample LLO-2 delivers a discharge specific capacity of 263.5 mA h g-1 at 0.1C and capacity retention rate with 88.1% at 0.2C after 100 cycles compared to 250.2 mA h g-1 and 75.6% for the pristine sample. The enhanced performance could be because Ce doping enlarges the lattice parameter, which may contribute to accelerating the Li+ diffusion rate. Moreover, the newly formed Li2CeO3 coating with oxygen vacancies could inhibit the loss of lattice oxygen and protect the electrode surface by suppressing the attack from the electrolyte. This work provides an effective approach to design Li-rich Mn-based layered oxides with improved electrochemical performance.

Bioinformatics investigation of adaptive immune-related genes in peri-implantitis and periodontitis: Characteristics and diagnostic values.

BACKGROUND: Peri-implantitis and periodontitis have similar immunological bioprocesses and inflammatory phenotypes. In the inflammatory process, the adaptive immune cells can drive the development of disease. This research investigated the differences and diagnostic significance of peri-implantitis and periodontitis in adaptive immune responses. METHODS: We acquired four GEO datasets of gene expressions in surrounding tissues in healthy person, healthy implant, periodontitis, and peri-implantitis patients. The structural characteristics and enrichment analyses of differential expression genes were examined. The adaptive immune landscapes in peri-implantitis and periodontitis were then evaluated using single sample gene set enrichment analysis. The STRING database and Cytoscape were used to identify adaptive hub genes, and the ROC curve was used to verify them. Finally, qRT-PCR method was used to verify the expression level of Hub gene in activated T cells on the titanium-containing or titanium-free culture plates. RESULTS: At the transcriptome level, the data of healthy implant, peri-implantitis and periodontitis were highly dissimilar. The peri-implantitis and periodontitis both exhibited adaptive immune response. Except for the activated CD4+T cells, there was no significant difference in other adaptive immune cells between peri-implantitis and periodontitis. In addition, correlation analysis showed that CD53, CYBB, and PLEK were significantly positively linked with activated CD4+T cells in the immune microenvironment of peri-implantitis, making them effective biomarkers to differentiate it from periodontitis. CONCLUSIONS: Peri-implantitis has a uniquely immunogenomic landscape that differs from periodontitis. This study provides new insights and ideas into the activated CD4+T cells and hub genes that underpin the immunological bioprocess of peri-implantitis.

Enhancing the reversibility of the chemical evolution of the Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode via a simple pre-oxidation process.

For developing commercially viable LiNi1-x-yMnxCoyO2 (NCM), it is necessary to alleviate the irreversible chemical process upon Li-ion insertion/extraction, which primarily accounts for prevailing capacity loss, impedance buildup as well as low columbic efficiency. To resolve this issue, we herein propose a simple but novel method to alter the chemical composition by a facile treatment of H2O2, which remarkably reduces the cation mixing of Li+/Ni2+ and residual lithium on the cathode. The tailored composition contributes great resistance to the structural reconstruction and enhancement in structural reversibility, as shown by in situ Raman and high-resolution transmission electron microscope (HRTEM) results. Thus, the modified sample outperforms the pristine one; it exhibits cyclability with 95.7% capacity retention over 300 cycles, high columbic efficiency and enhanced rate capability.