Improved structure stability and performance of a LiFeSO4F cathode material for lithium-ion batteries by magnesium substitution.

Tavorite LiFeSO4F with high Li-ion conductivity has been considered a promising alternative to LiFePO4. However, its poor cycle stability and low electronic conductivity limit the practical application of Tavorite LiFeSO4F. In the present study, we employ a solvothermal method to produce magnesium-substitution LiMgxFe1-xSO4F (x = 0, 0.02, 0.04) cathode materials in which the Mg substitutes the Fe(2) sites. The first-principles calculations demonstrate that Mg-substitution could reduce the bandgap of LiFeSO4F and increase its electronic conductivity to 2.5 × 10-11 S cm-1. Meanwhile, CI-NEB and BV calculations reveal that the diffusion energy barrier of lithium along the (100) direction after Mg substitution is lower than the pristine sample, and the electrochemical inactive Mg2+ could improve the structure stability. The results show that the Mg-substituted LiFeSO4F exhibits enhanced cycle stability and rate performance compared with the pristine LiFeSO4F, suggesting that the use of electrochemically inactive ion substitution may be critical for the development of high-performance LiFeSO4F cathode materials for lithium-ion batteries.

Sulfur-Decorated Ti3 C2 TX MXene for High-Performance Sodium/Potassium-Ion Batteries.

As post-lithium ion batteries, both sodium-ion batteries (SIBs) and potassium ion batteries (PIBs) possess great potential for large scale energy storage. However, the application of both SIBs and PIBs are hindered by the lack of suitable electrode materials. Here, we synthesized the sulfur decorated Ti3 C2 Tx (S-T3 C2 Tx ) MXene as electrode material for SIBs and PIBs. Thanks to the sulfur functional group and the formation of Ti-S bond, which facilitates the sodium in-/desertion and strengthens the potassium ion adsorption ability, as well as enhances ion reaction kinetics and improved structure stability, the S-T3 C2 Tx exhibit excellent sodium/potassium storage performance, high reversible capacities of 151 and 101 mAh g-1 at 0.1 mA g-1 were achieved for SIBs and PIBs, respectively. Moreover, the S-T3 C2 Tx exhibits remarkable long-term capacity stability at a high density of 500 mA g-1 , providing an impressive storage of 88 mAh g-1 for SIBs and 41 mAh g-1 for PIBs even after 2000 cycles. This work could give a deep comprehension of the heteroatom modification influence on the MXene-based framework and promote the application of MXene electrodes.

[Establishment of Quantitative SPR Assay for Antibodies Against Human Platelet Antigen-1a].

OBJECTIVE: To establish quantitative surface plasmon resonance (SPR) assay for antibodies against human platelet antigen-1a (HPA-1a). METHODS: Recombinant protein was fixed on the chip surface by amino coupling method. SPR assay was used to detect the standard antibodies against HPA-1a at different conceatration. The optimal experimental parameters were determined, and standard curves were constructed with linear regression. Moreover, the sensitivity, specificity, accuracy and precision of the assay were evaluated. RESULTS: The quantitative SPR assay for HPA-1a antibodies was established. The determination ranges were 0-20 IU, with accuracy (recovery rate) was 97.75%-103.08%. The intra-assay precision [coefficients of variation (CV)] was 3.53%-4.29%, and the inter-assay precision (CV) was 2.08%-4.40%. For specificity test, several kinds of monoclonal and human antibodies against platelet membrane protein were tested and no positive result was observed. CONCLUSION: The established quantitative SPR assay for HPA-1a antibodies shows good sensitivity, specificity, accuracy and precision, and this rapid and simple method provides a new reference method for scientific research and clinical antibody detection.