Nanjing University

About: Nanjing University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 85961 authors who have published 105504 publications receiving 2289036 citations. The organization is also known as: NJU & Nanking University.

Challenges and Recent Progress in the Development of Si Anodes for Lithium-Ion Battery

Abstract: Silicon, because of its high specific capacity, is intensively pursued as one of the most promising anode material for next-generation lithium-ion batteries. In the past decade, various nanostructures are successfully demonstrated to address major challenges for reversible Si anodes related to pulverization and solid-electrolyte interphase. However, the electrochemical performance is still limited by challenges that stem from the use of nanomaterials. In this progress report, the focus is on the challenges and recent progress in the development of Si anodes for lithium-ion battery, including initial Coulombic efficiency, areal capacity, and material cost, which call for more research effort and provide a bright prospect for the widespread applications of silicon anodes in the future lithium-ion batteries.

An organic-inorganic perovskite ferroelectric with large piezoelectric response

Abstract: Molecular piezoelectrics are highly desirable for their easy and environment-friendly processing, light weight, low processing temperature, and mechanical flexibility. However, although 136 years have passed since the discovery in 1880 of the piezoelectric effect, molecular piezoelectrics with a piezoelectric coefficient d33 comparable with piezoceramics such as barium titanate (BTO; ~190 picocoulombs per newton) have not been found. We show that trimethylchloromethyl ammonium trichloromanganese(II), an organic-inorganic perovskite ferroelectric crystal processed from aqueous solution, has a large d33 of 185 picocoulombs per newton and a high phase-transition temperature of 406 kelvin (K) (16 K above that of BTO). This makes it a competitive candidate for medical, micromechanical, and biomechanical applications.

Large Magnetic Entropy Change in Perovskite-Type Manganese Oxides

Abstract: Magnetic entropy change larger than that of gadolinium has been observed in polycrystalline of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ ( $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.2$ and 0.33) perovskite-type manganese oxide. The large magnetic entropy change produced by the abrupt reduction of magnetization is attributed to the anomalous thermal expansion just at the Curie temperature. The considerable magnetic entropy change was also observed in ${\mathrm{La}}_{0.75}{\mathrm{Sr}}_{0.25\ensuremath{-}y}{\mathrm{Ca}}_{y}{\mathrm{MnO}}_{3}$ near room temperature. The phenomenon of large magnetic entropy change and the convenient adjustment of the Curie temperature make the perovskite-type manganese oxides useful for magnetic refrigerants in an extended high temperature range even at room temperature.

Carbon-Based Metal-Free ORR Electrocatalysts for Fuel Cells: Past, Present, and Future.

Abstract: Replacing precious platinum with earth-abundant materials for the oxygen reduction reaction (ORR) in fuel cells has been the objective worldwide for several decades. In the last 10 years, the fastest-growing branch in this area has been carbon-based metal-free ORR electrocatalysts. Great progress has been made in promoting the performance and understanding the underlying fundamentals. Here, a comprehensive review of this field is presented by emphasizing the emerging issues including the predictive design and controllable construction of porous structures and doping configurations, mechanistic understanding from the model catalysts, integrated experimental and theoretical studies, and performance evaluation in full cells. Centering on these topics, the most up-to-date results are presented, along with remarks and perspectives for the future development of carbon-based metal-free ORR electrocatalysts.