Chang-Keun Back

Bio: Chang-Keun Back is an academic researcher. The author has contributed to research in topics: Anode & Nickel oxide. The author has an hindex of 2, co-authored 3 publications receiving 217 citations.

Recent advances in the electrolytes for interfacial stability of high-voltage cathodes in lithium-ion batteries

Abstract: Advanced electrolytes with unique functions such as in situ formation of a stable artificial solid electrolyte interphase (SEI) layer on the anode and the cathode, and the improvement in oxidation stability of the electrolyte have recently gained recognition as a promising means for highly reliable lithium-ion batteries with high energy density. In this review, we describe several challenges for the cathode (spinel lithium manganese oxide (LMO), lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), spinel lithium manganese nickel oxide (LNMO), and lithium-rich layered oxide (Li-rich cathode))-electrolyte interfaces and highlight the recent progress in the use of oxidative additives and high-voltage solvents in high-performance cells.

Activated natural porous silicate for a highly promising SiOx nanostructure finely impregnated with carbon nanofibers as a high performance anode material for lithium-ion batteries

Abstract: A highly promising anode material with an amorphous SiOx nanostructure finely impregnated with carbon nanofibers is presented. The nanostructure material has a unique integral feature in that carbon nanofibers smaller than several nm in diameter are finely dispersed in amorphous SiOx media in an aligned manner. The synthetic route to fabricate the nanostructure is very simple and easy, using natural porous silicate, sepiolite, activated through the process of sintering and acid treatments on carbon source-loaded sepiolite nanocomposites. Upon the treatments, the nanocomposite material is changed in respect of its structure and chemical composition from crystalline Mg silicate to the carbon nanofiber-impregnated amorphous SiOx phase (CNF–SiOx nanostructure), and the electrochemical activity is greatly improved. The CNF–SiOx nanostructure exhibits excellent electrochemical performance with a reasonably high capacity of approximately 720 mA h g−1 for a current density of 70 mA g−1 (C/10 rate) and outstanding rate capability with a capacity retention of 96.8% for a current density of 700 mA g−1 and 87% at 1400 mA g−1 relative to that at 35 mA g−1, even at a high electrode loading level above 8 mg cm−2. The cycling performance is also very stable, with a capacity retention of 94.7% over 50 cycles at a rate of 350 mA g−1 and with a Coulombic efficiency above 99%.

Recent Advances in the Electrolytes for Interfacial Stability of High‐Voltage Cathodes in Lithium‐Ion Batteries

Abstract: Advanced electrolytes with unique functions such as in situ formation of a stable artificial solid electrolyte interphase (SEI) layer on the anode and the cathode, and the improvement in oxidation stability of the electrolyte have recently gained recognition as a promising means for highly reliable lithium-ion batteries with high energy density. In this review, we describe several challenges for the cathode (spinel lithium manganese oxide (LMO), lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), spinel lithium manganese nickel oxide (LNMO), and lithium-rich layered oxide (Li-rich cathode))-electrolyte interfaces and highlight the recent progress in the use of oxidative additives and high-voltage solvents in high-performance cells.

High-voltage positive electrode materials for lithium-ion batteries

Abstract: The ever-growing demand for advanced rechargeable lithium-ion batteries in portable electronics and electric vehicles has spurred intensive research efforts over the past decade. The key to sustaining the progress in Li-ion batteries lies in the quest for safe, low-cost positive electrode (cathode) materials with desirable energy and power capabilities. One approach to boost the energy and power densities of batteries is to increase the output voltage while maintaining a high capacity, fast charge–discharge rate, and long service life. This review gives an account of the various emerging high-voltage positive electrode materials that have the potential to satisfy these requirements either in the short or long term, including nickel-rich layered oxides, lithium-rich layered oxides, high-voltage spinel oxides, and high-voltage polyanionic compounds. The key barriers and the corresponding strategies for the practical viability of these cathode materials are discussed along with the optimization of electrolytes and other cell components, with a particular emphasis on recent advances in the literature. A concise perspective with respect to plausible strategies for future developments in the field is also provided.

Electrolyte Additives for Lithium Metal Anodes and Rechargeable Lithium Metal Batteries: Progress and Perspectives.

Abstract: Lithium metal (Li0 ) rechargeable batteries (LMBs), such as systems with a Li0 anode and intercalation and/or conversion type cathode, lithium-sulfur (Li-S), and lithium-oxygen (O2 )/air (Li-O2 /air) batteries, are becoming increasingly important for electrifying the modern transportation system, with the aim of sustainable mobility. Although some rechargeable LMBs (e.g. Li0 /LiFePO4 batteries from Bollore Bluecar, Li-S batteries from OXIS Energy and Sion Power) are already commercially viable in niche applications, their large-scale deployment is hampered by a number of formidable challenges, including growth of lithium dendrites, electrolyte instability towards high voltage intercalation-type cathodes, the poor electronic and ionic conductivities of sulfur (S8 ) and O2 , as well as their corresponding reduction products (e.g. Li2 S and Li2 O), dissolution, and shuttling of polysulfide (PS) intermediates. This leads to a short lifecycle, low coulombic/energy efficiency, poor safety, and a high self-discharge rate. The use of electrolyte additives is considered one of the most economical and effective approaches for circumventing these problems. This Review gives an overview of the various functional additives that are being applied and aims to stimulate new avenues for the practical realization of these appealing devices.