Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Microstructure. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Facile fabrication of a nanoporous silicon electrode with superior stability for lithium ion batteries

Abstract: In this paper, we demonstrate that a novel silicon electrode with a large amount of nanopores can be fabricated by an in-situ thermal generating approach using triethanolamine as a sacrificing template. The fabrication process is simple, green, low cost, and easy to be scaled up. This electrode achieves high reversible capacities (2500 mAh g−1) with excellent cycling stability (∼90% capacity retention after 100 charge–discharge cycles), showing great potential as a high-performance anode for lithium-ion batteries. It is revealed that the high void volume with pore size of <200 nm can both enlarge the interface between active silicon particles and the electrolyte, and accommodate the severe volume change of silicon, thus leading to remarkably improved reversible capacity and cycling stability. The design concept and the fabrication approach used in the nanoporous silicon electrode may also be extended to other electrodes for electrochemical applications.

Top-down synthesis of muscle-inspired alluaudite Na2+2xFe2−x(SO4)3/SWNT spindle as a high-rate and high-potential cathode for sodium-ion batteries

Abstract: The tailoring of materials into bio-inspired structures is triggering unprecedented innovations. Muscle tissue is composed of myofibrils and densely wired blood vessels; it is a perfect model for designing high-performance electrode materials that have the advantage of fast mass transport and superior durability. We design a top-down strategy as a facile approach to tailor the alluaudite Na2+2xFe2−x(SO4)3 into a muscle-like spindle. A precipitation process is employed to prepare the hydrated “top” precursor, which is subjected to dehydration and phase transformation to obtain the “down” product. The alluaudite sulfate nanoparticles closely anchor on the single-wall carbon nanotubes (SWNT), and they together aggregate into microscale particles in the shape of spindles. The Na2+2xFe2−x(SO4)3/SWNT composite as a whole copies the morphology and function of muscle tissue. Taking advantage of its 3D conductive framework and porous structure, the composite achieves fast electron/ion transport and sodium intercalation. Moreover, the single-phase reaction mechanism during sodium intercalation is beneficial to its cycling property. It exhibits such desirable electrochemical performance as an operating potential as high as ∼3.8 V and a high-rate capability, which achieves a capacity retention of 92% after 100 cycles at 5C. The muscle-inspired architecture makes electrode materials favorable for superior electrochemical performance.