http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Electrochemical Properties of Rechargeable Organic Radical Battery with PTMA Cathode
김재광,Gouri Cheruvally,Ghanshyam S. Chauhan,최재원,김둘선,안효준,이서환,송충의,안주현 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.1
The electrochemical properties of the organic radical battery (ORB) having a lithium metal anode and a cathode consisting of a nitroxide radical polymer poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) with 1M LiPF6 as an electrolyte in ethylene carbonate (EC)/dimethyl carbonate (DMC) have been evaluated at room temperature. The cell, with a thin cathode of 17 μm thickness incorporating 40 wt.% of PTMA, exhibited the full theoretical specific capacity at current densities up to 10 C (~1 mA/cm² ). However, a decrease in the specific capacity and an increase in the ohmic resistance were observed at higher current densities. The cell performance was good even on repeated charge-discharge cycles as an excess of 85 % retention of the initial discharge capacity was observed. This was true even after 400 cycles. However, a gradual decrease in capacity, an increase in charge-discharge voltage separation, and an electrode/electrolyte interfacial resistance have been observed after a large number of cycles. The examination of the scanning electron micrographs of the cathode material revealed that prolonged cycling resulted in the agglomeration of PTMA particles. These in turn increased the resistance and decreased the capacity of the cell. The electrochemical properties of the organic radical battery (ORB) having a lithium metal anode and a cathode consisting of a nitroxide radical polymer poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) with 1M LiPF6 as an electrolyte in ethylene carbonate (EC)/dimethyl carbonate (DMC) have been evaluated at room temperature. The cell, with a thin cathode of 17 μm thickness incorporating 40 wt.% of PTMA, exhibited the full theoretical specific capacity at current densities up to 10 C (~1 mA/cm² ). However, a decrease in the specific capacity and an increase in the ohmic resistance were observed at higher current densities. The cell performance was good even on repeated charge-discharge cycles as an excess of 85 % retention of the initial discharge capacity was observed. This was true even after 400 cycles. However, a gradual decrease in capacity, an increase in charge-discharge voltage separation, and an electrode/electrolyte interfacial resistance have been observed after a large number of cycles. The examination of the scanning electron micrographs of the cathode material revealed that prolonged cycling resulted in the agglomeration of PTMA particles. These in turn increased the resistance and decreased the capacity of the cell.
Organic radical battery with PTMA cathode: Effect of PTMA content on electrochemical properties
김재광,송충의,Gouri Cheruvally,서양곤,최두성,Seo-Hwan Lee,안주현 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.3
The nitroxide radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxy-4-ylmethacrylate) (PTMA) is gaining increasing attention as a promising cathode-active material for high-rate capable, organic radical batteries (ORBs). This study evaluates the effect of varying PTMA content (20, 40 and 60wt.%) on the cathode morphology and electrochemical properties of the ORB operating at room temperature with lithium metal anode and 1M LiPF6 in ethylene carbonate (EC)/dimethyl carbonate (DMC) electrolyte. The cathodes with 20 and 40% of PTMA exhibited uniform particle morphology with a thin layer of polymer coating and these resulted in achieving 100% utilization of the active material (111mAh/g specific capacity for the cell) at moderate C-rates. The cathode with 60% of PTMA exhibited larger ohmic resistance and lower chargedischarge properties due to the thicker layer of insulating polymer. The maximum discharge capacities at very high C-rates of 30 and 50C were realized from the 20% PTMA cathode that has the highest carbon content and hence the lowest ohmic resistance. The Li/PTMA cells exhibited good performance on long-term cycling at 1C, irrespective of the PTMA content in the cathode.
Lithium/Sulfur Secondary Batteries: A Review
Zhao, Xiaohui,Cheruvally, Gouri,Kim, Changhyeon,Cho, Kwon-Koo,Ahn, Hyo-Jun,Kim, Ki-Won,Ahn, Jou-Hyeon The Korean Electrochemical Society 2016 Journal of electrochemical science and technology Vol.7 No.2
Lithium batteries based on elemental sulfur as the cathode-active material capture great attraction due to the high theoretical capacity, easy availability, low cost and non-toxicity of sulfur. Although lithium/sulfur (Li/S) primary cells were known much earlier, the interest in developing Li/S secondary batteries that can deliver high energy and high power was actively pursued since early 1990’s. A lot of technical challenges including the low conductivity of sulfur, dissolution of sulfur-reduction products in the electrolyte leading to their migration away from the cathode, and deposition of solid reaction products on cathode matrix had to be tackled to realize a high and stable performance from rechargeable Li/S cells. This article presents briefly an overview of the studies pertaining to the different aspects of Li/S batteries including those that deal with the sulfur electrode, electrolytes, lithium anode and configuration of the batteries.