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4. Multi-scale boron penetration toward stabilizing nickel-rich cathode

Author

You, Bianzheng, Wang, Zhixing, Chang, Yijiao, Yin, Wei, Xu, Zhengwei, Zeng, Yuexi, Yan, Guochun, and Wang, Jiexi

Subjects
Engineering, Materials Engineering, Chemical Sciences, Physical Chemistry, Gas evolution, Intergranular cracks, Lithium borates, Lithium-ion diffusion kinetics, Nickel-rich layered oxides, Trace boron doping
Abstract

Nickel-rich layered oxides LiNi x Co y Mn1- x - y O2 (x ≥ 0.8) have been recognized as the preferred cathode materials to develop lithium-ion batteries with high energy density (>300 Wh kg-1). However, the poor cycling stability and rate capability stemming from intergranular cracks and sluggish kinetics hinder their commercialization. To address such issues, a multi-scale boron penetration strategy is designed and applied on the polycrystalline LiNi0.83Co0.11Mn0.06O2 particles that are pre-treated with pore construction. The lithium-ion conductive lithium borate in grain gaps functions as the grain binder that can bear the strain/stress from anisotropic contraction/expansion, and provides more pathways for lithium-ion diffusion. As a result, the intergranular cracks are ameliorated and the lithium-ion diffusion kinetics is improved. Moreover, the coating layer separates the sensitive cathode surface and electrolyte, helping to suppress the parasitic reactions and related gas evolution. In addition, the enhanced structural stability is acquired by strong B-O bonds with trace boron doping. As a result, the boron-modified sample with an optimized boron content of 0.5% (B5-NCM) exhibits a higher initial discharge capacity of 205.5 mAh g-1 at 0.1C (1C = 200 mA g-1) and improved capacity retention of 81.7% after 100 cycles at 1C. Furthermore, the rate performance is distinctly enhanced by high lithium-ion conductive LBO (175.6 mAh g-1 for B5-NCM and 154.6 mAh g-1 for B0-NCM at 5C).

Published
2023

13. Research on Data Watermark Tracing System in Hadoop Environment

Author

Qiao, Wenyu, Wang, Jiexi, Filipe, Joaquim, Editorial Board Member, Ghosh, Ashish, Editorial Board Member, Prates, Raquel Oliveira, Editorial Board Member, Zhou, Lizhu, Editorial Board Member, Tian, Yuan, editor, Ma, Tinghuai, editor, Jiang, Qingshan, editor, Liu, Qi, editor, and Khan, Muhammad Khurram, editor

Published
2023
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14. Change in Invasively Measured Mean Pulmonary Artery Pressure After Transcatheter Mitral Valve Repair Is Associated With Heart Failure Readmission.

Author

Tehrani, David M, Wang, Jiexi, Lai, Parntip, Desai, Pooja S, Nguyen, Heajung L, Bang, Lisa, Yang, Eric H, Vorobiof, Gabriel, Nsair, Ali, Aksoy, Olcay, Press, Marcella Calfon, and Parikh, Rushi V

Abstract

Pre-existing pulmonary hypertension is associated with poor outcomes after transcatheter mitral valve repair (TMVr) for mitral regurgitation (MR). However, the impact of an immediate change in mean pulmonary artery pressure (ΔmPAP) following TMVr on outcomes is unknown.Patients who underwent TMVr from December 2015 to February 18, 2020 at our institution for symptomatic 3-4+ MR and who had invasive hemodynamics measured immediately pre- and post-TMVR were included. Multivariate Cox regression analysis was performed to examine the association of ΔmPAP (post-TMVr - pre-TMVr mPAP) with the primary endpoint of heart failure (HF) readmission at 1 year. Secondary endpoints included all-cause mortality and the composite endpoint of HF readmission or all-cause mortality at 1 year.Among 55 patients, 55% were men, mean age was 72 ± 14.2 years, and mean ΔmPAP was -1.4 ± 8.2 mm Hg. Overall, HF readmission occurred in 14 (25%), death in 10 (18%), and the composite endpoint in 20 (36%) patients. In multivariable analyses, higher ΔmPAP was significantly associated with HF readmission (hazard ratio (HR) = 1.10, 95% confidence interval (CI): 1.00 - 1.21; P = 0.04). ΔmPAP was not associated with death (HR = 1.04, 95% CI: 0.96 - 1.14; P = 0.33), though there was a numerical but statistically non-significant trend towards the composite endpoint (HR = 1.06, 95% CI: 1.00 - 1.13; P = 0.06) driven by HF readmission.Higher ΔmPAP immediately following TMVr was associated with increased HF readmission at 1 year. Larger prospective studies are needed to validate these data and further explore the utility of ΔmPAP as a novel hemodynamic parameter to predict post-TMVR outcomes.

Published
2021

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