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2. Silicon–Nanodiamond-Based Anode for a Lithium-Ion Battery.

Author

Jhan, Cheng-Ying, Sung, Shi-Hong, and Tzeng, Yonhua

Subjects
LITHIUM-ion batteries, ANODES, NANODIAMONDS, SOLID electrolytes, NANOSILICON, SILICON surfaces, RAMAN spectroscopy, X-ray diffraction
Abstract

Maintaining the physical integrity of a silicon-based anode, which suffers from damage caused by severe volume changes during cycling, is a top priority in its practical applications. The performance of silicon-flake-based anodes has been significantly improved by mixing nanodiamond powders with silicon flakes for the fabrication of anodes for lithium-ion batteries (LIBs). Nanodiamonds adhere to the surfaces of silicon flakes and are distributed in the binder between flakes. A consistent and robust solid electrolyte interphase (SEI) is promoted by the aid of abundant reactive surface-linked functional groups and exposed dangling bonds of nanodiamonds, leading to enhanced physical integrity of the silicon flakes and the anode. The battery's high-rate discharge capabilities and cycle life are thus improved. SEM, Raman spectroscopy, and XRD were applied to examine the structure and morphology of the anode. Electrochemical performance was evaluated to demonstrate a capacity retention of nearly 75% after 200 cycles, with the final specific capacity exceeding 1000 mAh/g at a test current of 4 mA/cm2. This is attributed to the improved stability of the solid electrolyte interphase (SEI) structure that was achieved by integrating nanodiamonds with silicon flakes in the anode, leading to enhanced cycling stability and rapid charge-discharge performance. The results from this study present an effective strategy of achieving high-cycling-performance by adding nanodiamonds to silicon-flake-based anodes. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Carboxylated nanodiamond-mediated CRISPR-Cas9 delivery of human retinoschisis mutation into human iPSCs and mouse retina

Author

Yang, Tien-Chun, primary, Chang, Chia-Yu, additional, Yarmishyn, Aliaksandr A., additional, Mao, Yen-Shiang, additional, Yang, Yi-Ping, additional, Wang, Mong-Lien, additional, Hsu, Chih-Chien, additional, Yang, Hsin-Yu, additional, Hwang, De-Kuang, additional, Chen, Shih-Jen, additional, Tsai, Ming-Long, additional, Lai, Yun-Hsien, additional, Tzeng, Yonhua, additional, Chang, Chia-Ching, additional, and Chiou, Shih-Hwa, additional

Published
2020
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33. The effect of space charge induced by an electon beam on spark gap operation

Author

Tzeng, Yonhua

Subjects
Electric spark gaps, Electron beams, Electric discharges through gases, Breakdown voltage, Space charge
Abstract

An investigation into the effect of electron beam induced space charge on the insulating property of a gas in a spark gap is presented. The characteristics of the gas transition from insulator to conductor show strong dependence on the amount and location of the space charge introduced. Investigations of the delay time and the characteristics of the conducting channel have been made. The delay time from the injection of the electron beam to the collapse of the gap voltage ranges from 10^-9 to 10^-3 second. From open shutter photography, we observe that the character of the conducting channel is quite varied. Dark, diffuse, filamentary, or diffuse followed by filamentary (single or multi) channels have been observed, depending on the space charge conditions. The fundamental processes leading to the collapse of insulating property of the gas for various experimental conditions are discussed.

Published
1981

34. An investigation of non-equilibrium electron kinetics in nitrogen

Author

Tzeng, Yonhua

Subjects
Monte Carlo method, Electric fields, Collisions (Nuclear physics), Kinetic theory of gases, Electrons, Ionized gases
Abstract

The kinetic behavior of electrons immersed in a background gas or gas mixture under the action of an externally applied electric field with or without the influence of the space charge induced electric fields have been investigated. Novel Monte Carlo techniques have been developed and applied to study the evolution of the electrons self-consistently , that is, including the effects of the electric field generated by the space charge and the effects of boundaries. Statistical fluctuations of the macroscopic variables describing the evolution of the electron assembly have been studied. This is important when the total number of electrons is less than about 100. Ensemble averaged descriptions, kinetic in nature, have been used to study the development of an avalanche and the formation and propagation of a streamer. The results from this research program have provided key fundamental knowledge necessary for the explanation of the approach to equilibrium of an assembly of electrons, the effects of scattering processes on the electron velocity distribution, prebreakdown phenomena and manipulating the dielectric properties of gas mixtures used in insulating and switching applications.

Published
1983

35. Effects of post-deposition heat treatment and hydrogenation on electrical conductivity of nanodiamond films

Author

Chen, Yu-Chun, Cheng, An-Jen, Clark, Maurice, Liu, Yen-Kang, and Tzeng, Yonhua

Subjects
*HEAT treatment of metals, *NITROGEN, *HYDROGENATION, *VAPOR-plating
Abstract

Abstract: Effects of post-deposition hydrogenation on electrical conductivity of intrinsic and nitrogen doped nanodiamonds have been characterized. Nanodiamond films were deposited by means of microwave plasma assisted chemical vapor deposition in gas mixtures of methane and argon with little or without hydrogen additives. For nitrogen doped nanodiamonds, nitrogen gas of varied flow rates was added to the gas mixture of methane and argon as a dopant. Electrical conductivity of as-grown nanodiamond films was measured by either (i) directly measuring the conductivity of a metal/nanodiamond/metal sandwich test structure or (ii) applying an electrical current through two terminals of a van der Pauw test structure while measuring the voltage across the other two terminals on corners of a nanodiamond film that was deposited on an electrically insulating surface of a substrate. The same measurement was repeated after subjecting the nanodiamond to a heat treatment and later repeated again after exposing the nanodiamond to hydrogen plasma. Effects of the heat treatment and the plasma hydrogenation on electrical conductivity of nanodiamond are reported and discussed. [Copyright &y& Elsevier]

Published
2006
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