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Shinichi Komaba - One of the best experts on this subject based on the ideXlab platform.
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MgO‐Template Synthesis of Extremely High Capacity Hard Carbon for Na‐Ion Battery
Angewandte Chemie (International ed. in English), 2021Co-Authors: Azusa Kamiyama, Kazuma Gotoh, Kei Kubota, Daisuke Igarashi, Yong Youn, Yoshitaka Tateyama, Hideka Ando, Shinichi KomabaAbstract:Extremely high capacity Hard Carbon for Na-ion battery, delivering 478 mAh g-1 , is successfully synthesized by heating a freeze-dried mixture of magnesium gluconate and glucose by a MgO-template technique. Influences of synthetic conditions and nano-structures on electrochemical Na storage properties in the Hard Carbon are systematically studied to maximize the reversible capacity. Nano-sized MgO particles are formed in a Carbon matrix prepared by pre-treatment of the mixture at 600 °C. Through acid leaching of MgO and Carbonization at 1500 °C, resultant Hard Carbon demonstrates an extraordinarily large reversible capacity of 478 mAh g-1 with a high Coulombic efficiency of 88 % at the first cycle.
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Unveiling pseudocapacitive behavior of Hard Carbon anode materials for sodium-ion batteries
Electrochimica Acta, 2020Co-Authors: Zoia V. Bobyleva, Shinichi Komaba, Azusa Kamiyama, Oleg A. Drozhzhin, Kirill A. Dosaev, Sergey V. Ryazantsev, Evgeny V. AntipovAbstract:Abstract Hard Carbon is the most prospective anode material for sodium-ion batteries with outstanding electrochemical performance. However, the type of reaction associated with charge storage is a subject of contentious deliberations within the scientific society. We examined the pseudocapacitive behavior of glucose-derived Hard Carbon with different porosity by detailed linear sweep voltammetric analysis which demonstrated the presence of three distinct processes occurring during Na+-deinsertion. A combination of pseudocapacitive-intercalation-pseudocapacitive behavior for all synthesized Hard Carbons is proposed. Obtained results differ drastically from the behavior demonstrated by graphite/Li cell, soft Carbon/Na cell and pure Na metal plating.
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High-Capacity Hard Carbon Synthesized from Macroporous Phenolic Resin for Sodium-Ion and Potassium-Ion Battery
ACS Applied Energy Materials, 2019Co-Authors: Azusa Kamiyama, Kei Kubota, Takeshi Nakano, Shun Fujimura, Soshi Shiraishi, Hidehiko Tsukada, Shinichi KomabaAbstract:Hard Carbon is synthesized by heat-treating macroporous phenolic resin at different temperatures. We study influences of temperature on the structures and electrode properties of the Hard Carbon in...
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Synthesis of Hard Carbon from argan shells for Na-ion batteries
Journal of Materials Chemistry A, 2017Co-Authors: Mouad Dahbi, Manami Kiso, Kei Kubota, Tatsuo Horiba, Tarik Chafik, Kazuo Hida, Takashi Matsuyama, Shinichi KomabaAbstract:Hard Carbon is an attractive material for negative electrodes in sodium-ion batteries. Herein, we report a new Hard Carbon synthesized via Carbonization of argan shell biomass, which delivers an enhanced capacity higher than 330 mA h g−1 based upon reversible sodium insertion. We prepared Hard Carbon under different high-temperature treatment and biomass pretreatment conditions. The graphitization degree of the Hard Carbon increased as the Carbonization temperature increased; simultaneously, the reversible capacity for sodium storage was significantly influenced by the Carbonization temperature. Structural characterization revealed differences in the structures of the Hard Carbons synthesized at different Carbonization temperatures, which elucidates the correlation between the increased capacity and the micropore size available for sodium storage. The composite electrodes containing the argan Hard Carbons with a sodium polyacrylate binder were tested in non-aqueous sodium half cells. The electrodes delivered reversible capacities as high as 300 mA h g−1 at a current density of 25 mA g−1 with superior reversibility and capacity retention of 94.1% after 70 cycles. By Carbonization of argan shell biomass treated with HCl aqueous solution, we successfully demonstrated a higher reversible capacity of 333 mA h g−1 and an excellent capacity retention of 96.0% after 100 cycles.
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Effect of Hexafluorophosphate and Fluoroethylene Carbonate on Electrochemical Performance and the Surface Layer of Hard Carbon for Sodium‐Ion Batteries
ChemElectroChem, 2016Co-Authors: Mouad Dahbi, Naoaki Yabuuchi, Kei Kubota, Takeshi Nakano, Shun Fujimura, Kuniko Chihara, Jin-young Son, Yi-tao Cui, Hiroshi Oji, Shinichi KomabaAbstract:Electrochemical sodium insertion for Hard Carbon is examined in a cyclic alkylene Carbonate based solution containing a NaClO4 or NaPF6 salt with a fluoroethylene Carbonate (FEC) additive to study electrolyte dependency for sodium-ion batteries. NaPF6-based electrolytes provide superior reversibility and cyclability of sodium insertion into Hard Carbon compared with NaClO4-based ones. The FEC-derived passivation film improves capacity retention because of better passivation with a thinner surface layer, as revealed by Hard and soft X-ray photoelectron spectroscopy (PES). The use of both the NaPF6 salt and FEC additive results in a synergetic effect on passivation for the Hard-Carbon electrode, leading to enhanced cycle performance. Hard-Carbon electrodes with polyvinylidene difluoride binder in propylene Carbonate based electrolytes containing NaPF6 and FEC demonstrate excellent capacity retention with a reversible capacity of about 250 mAh g−1. The difference in capacity retention for the electrolytes is expected to originate as a consequence of the difference in the surface interphase layer formed on the Hard-Carbon electrodes. Surface analyses with PES and time-of-flight secondary ion mass spectrometry reveal differences in surface and passivation chemistry which depend on the salts, solvents, and FEC additives used for the Hard-Carbon negative electrodes.
Mouad Dahbi - One of the best experts on this subject based on the ideXlab platform.
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Structural Analysis of Sucrose-Derived Hard Carbon and Correlation with the Electrochemical Properties for Lithium, Sodium, and Potassium Insertion
Chemistry of Materials, 2020Co-Authors: Kei Kubota, Kazuma Gotoh, Saori Shimadzu, Naoaki Yabuuchi, Soshi Shiraishi, Satoshi Tominaka, Maria Abreu-sepulveda, Ayyakkannu Manivannan, Mika Fukunishi, Mouad DahbiAbstract:Hard Carbon possesses the ability to store Li, Na, and K ions between stacked sp2 Carbon layers and voids (micropores). We have explored Hard Carbon as a candidate for negative electrode materials ...
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P-doped Hard Carbon as Anode Material for Sodium-ion Batteries
2019 7th International Renewable and Sustainable Energy Conference (IRSEC), 2019Co-Authors: Charifa Hakim, Habtom Desta Asfaw, Mouad Dahbi, Daniel Brandell, Kristina Edström, Reza Younesi, Ismael SaadouneAbstract:The P-doped Hard Carbon was synthesized using carboxymethyl cellulose and phosphoric acid as the Carbon and phosphorus precursors, respectively. The X-ray photoelectron spectroscopy (XPS) analysis reveals that the doped phosphorus atoms can incorporate into the Carbon framework and most of them are connecting with Carbon atoms to form P-C bonds. When used as anodes in sodium ion batteries, the obtained un-doped and P-doped Hard Carbon show poor electrochemical performances. The results indicate further optimization of the synthesis process is required. However, this approach opens up new possibilities to improve electrochemical performance of Hard Carbon anodes.
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Synthesis of Hard Carbon from argan shells for Na-ion batteries
Journal of Materials Chemistry A, 2017Co-Authors: Mouad Dahbi, Manami Kiso, Kei Kubota, Tatsuo Horiba, Tarik Chafik, Kazuo Hida, Takashi Matsuyama, Shinichi KomabaAbstract:Hard Carbon is an attractive material for negative electrodes in sodium-ion batteries. Herein, we report a new Hard Carbon synthesized via Carbonization of argan shell biomass, which delivers an enhanced capacity higher than 330 mA h g−1 based upon reversible sodium insertion. We prepared Hard Carbon under different high-temperature treatment and biomass pretreatment conditions. The graphitization degree of the Hard Carbon increased as the Carbonization temperature increased; simultaneously, the reversible capacity for sodium storage was significantly influenced by the Carbonization temperature. Structural characterization revealed differences in the structures of the Hard Carbons synthesized at different Carbonization temperatures, which elucidates the correlation between the increased capacity and the micropore size available for sodium storage. The composite electrodes containing the argan Hard Carbons with a sodium polyacrylate binder were tested in non-aqueous sodium half cells. The electrodes delivered reversible capacities as high as 300 mA h g−1 at a current density of 25 mA g−1 with superior reversibility and capacity retention of 94.1% after 70 cycles. By Carbonization of argan shell biomass treated with HCl aqueous solution, we successfully demonstrated a higher reversible capacity of 333 mA h g−1 and an excellent capacity retention of 96.0% after 100 cycles.
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Effect of Hexafluorophosphate and Fluoroethylene Carbonate on Electrochemical Performance and the Surface Layer of Hard Carbon for Sodium‐Ion Batteries
ChemElectroChem, 2016Co-Authors: Mouad Dahbi, Naoaki Yabuuchi, Kei Kubota, Takeshi Nakano, Shun Fujimura, Kuniko Chihara, Jin-young Son, Yi-tao Cui, Hiroshi Oji, Shinichi KomabaAbstract:Electrochemical sodium insertion for Hard Carbon is examined in a cyclic alkylene Carbonate based solution containing a NaClO4 or NaPF6 salt with a fluoroethylene Carbonate (FEC) additive to study electrolyte dependency for sodium-ion batteries. NaPF6-based electrolytes provide superior reversibility and cyclability of sodium insertion into Hard Carbon compared with NaClO4-based ones. The FEC-derived passivation film improves capacity retention because of better passivation with a thinner surface layer, as revealed by Hard and soft X-ray photoelectron spectroscopy (PES). The use of both the NaPF6 salt and FEC additive results in a synergetic effect on passivation for the Hard-Carbon electrode, leading to enhanced cycle performance. Hard-Carbon electrodes with polyvinylidene difluoride binder in propylene Carbonate based electrolytes containing NaPF6 and FEC demonstrate excellent capacity retention with a reversible capacity of about 250 mAh g−1. The difference in capacity retention for the electrolytes is expected to originate as a consequence of the difference in the surface interphase layer formed on the Hard-Carbon electrodes. Surface analyses with PES and time-of-flight secondary ion mass spectrometry reveal differences in surface and passivation chemistry which depend on the salts, solvents, and FEC additives used for the Hard-Carbon negative electrodes.
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sodium carboxymethyl cellulose as a potential binder for Hard Carbon negative electrodes in sodium ion batteries
Electrochemistry Communications, 2014Co-Authors: Toru Ishikawa, Mouad Dahbi, Naoaki Yabuuchi, Kei Kubota, Takeshi Nakano, Mika Fukunishi, Sota ShibaharaAbstract:Abstract For a non-aqueous sodium-ion battery, a Hard-Carbon negative electrode with sodium carboxymethyl cellulose (CMC) binder demonstrates the superior reversibility and cycleability in NaPF6 propylene Carbonate solution at room temperature to that with ordinary poly(vinylidene difluoride) (PVdF) binder. Furthermore, effects of monofluoroethylene Carbonate (FEC) additive remarkably depend on the combination with binders, CMC and PVdF. Surface analyses reveal considerable differences in surface and passivation chemistry which depends on the binders and FEC additive used for the Hard-Carbon negative electrodes.
Kazuma Gotoh - One of the best experts on this subject based on the ideXlab platform.
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MgO‐Template Synthesis of Extremely High Capacity Hard Carbon for Na‐Ion Battery
Angewandte Chemie (International ed. in English), 2021Co-Authors: Azusa Kamiyama, Kazuma Gotoh, Kei Kubota, Daisuke Igarashi, Yong Youn, Yoshitaka Tateyama, Hideka Ando, Shinichi KomabaAbstract:Extremely high capacity Hard Carbon for Na-ion battery, delivering 478 mAh g-1 , is successfully synthesized by heating a freeze-dried mixture of magnesium gluconate and glucose by a MgO-template technique. Influences of synthetic conditions and nano-structures on electrochemical Na storage properties in the Hard Carbon are systematically studied to maximize the reversible capacity. Nano-sized MgO particles are formed in a Carbon matrix prepared by pre-treatment of the mixture at 600 °C. Through acid leaching of MgO and Carbonization at 1500 °C, resultant Hard Carbon demonstrates an extraordinarily large reversible capacity of 478 mAh g-1 with a high Coulombic efficiency of 88 % at the first cycle.
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Structural Analysis of Sucrose-Derived Hard Carbon and Correlation with the Electrochemical Properties for Lithium, Sodium, and Potassium Insertion
Chemistry of Materials, 2020Co-Authors: Kei Kubota, Kazuma Gotoh, Saori Shimadzu, Naoaki Yabuuchi, Soshi Shiraishi, Satoshi Tominaka, Maria Abreu-sepulveda, Ayyakkannu Manivannan, Mika Fukunishi, Mouad DahbiAbstract:Hard Carbon possesses the ability to store Li, Na, and K ions between stacked sp2 Carbon layers and voids (micropores). We have explored Hard Carbon as a candidate for negative electrode materials ...
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NMR study for electrochemically inserted Na in Hard Carbon electrode of sodium ion battery
Journal of Power Sources, 2013Co-Authors: Kazuma Gotoh, Toru Ishikawa, Shinichi Komaba, Saori Shimadzu, Naoaki Yabuuchi, Kazuyuki Takeda, Atsushi Goto, Kenzo Deguchi, Shinobu Ohki, Kenjiro HashiAbstract:Abstract The state of sodium inserted in the Hard Carbon electrode of a sodium ion battery having practical cyclability was investigated using solid state 23 Na NMR. The spectra of Carbon samples charged (reduced) above 50 mAh g −1 showed clear three components. Two peaks at 9.9 ppm and 5.2 ppm were ascribed to reversible sodium stored between disordered graphene sheets in Hard Carbon because the shift of the peaks was invariable with changing strength of external magnetic field. One broad signal at about −9 to −16 ppm was assigned to sodium in heterogeneously distributed closed nanopores in Hard Carbon. Low temperature 23 Na static and magic angle spinning NMR spectra didn't split or shift whereas the spectral pattern of 7 Li NMR for lithium-inserted Hard Carbon changes depending on the temperature. This strongly suggests that the exchange of sodium atoms between different sites in Hard Carbon is slow. These studies show that sodium doesn't form quasi-metallic clusters in closed nanopores of Hard Carbon although sodium assembles at nanopores while the cell is electrochemically charged.
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Pore Structure of Hard Carbon Made from Phenolic Resin Studied by 129Xe NMR
Bulletin of the Chemical Society of Japan, 2009Co-Authors: Kazuma Gotoh, Takahiro Ueda, Taro Eguchi, Koji Kawabata, Kenji Yamamoto, Yuki Murakami, Satoshi Hayakawa, Hiroyuki IshidaAbstract:The pore structure of Hard Carbon samples made from two kinds of phenolic resins by heating between 1073 and 1473 K was investigated by 129Xe NMR. The difference of porous structure of Hard Carbon ...
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Observation of micropores in Hard-Carbon using 129Xe NMR porosimetry
Journal of Physics and Chemistry of Solids, 2008Co-Authors: Kazuma Gotoh, Takahiro Ueda, Hironori Omi, Taro Eguchi, Mariko Maeda, Michihisa Miyahara, Aisaku Nagai, Hiroyuki IshidaAbstract:Abstract The existence of micropores and the change of surface structure in pitch-based Hard-Carbon in xenon atmosphere were demonstrated using 129 Xe NMR. For high-pressure (4.0 MPa) 129 Xe NMR measurements, the Hard-Carbon samples in Xe gas showed three peaks at 27, 34 and 210 ppm. The last was attributed to the xenon in micropores (
Chao Lai - One of the best experts on this subject based on the ideXlab platform.
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A type of sodium-ion full-cell with a layered NaNi0.5Ti0.5O2 cathode and a pre-sodiated Hard Carbon anode
RSC Advances, 2015Co-Authors: Hongbo Wang, Yazhou Xiao, Chuang Sun, Chao LaiAbstract:A new structure of sodium-ion full-cell with a layered NaNi0.5Ti0.5O2 cathode and a pre-sodiated Hard Carbon anode is reported. The pre-sodiation of the Hard Carbon anode, achieved via a facile approach in a three-electrode battery, can significantly enhance the initial coulombic efficiency of the sodium-ion full-cell. As a consequence, a much higher capacity is obtained in the Hard Carbon/NaNi0.5Ti0.5O2 sodium-ion battery. Based on the cathode mass, the full-cell with the pre-sodiated Hard Carbon anode can exhibit a reversible capacity of 93 mA h g−1.
Clement Bommier - One of the best experts on this subject based on the ideXlab platform.
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Mechanism of Na‐Ion Storage in Hard Carbon Anodes Revealed by Heteroatom Doping
Advanced Energy Materials, 2017Co-Authors: Clement Bommier, Zelang Jian, William F. Stickle, Joerg C. Neuefeind, Xingfeng Wang, Zhi Sen Chong, Todd Wesley Surta, Zhenyu Xing, Michelle R. DolgosAbstract:Hard Carbon is the leading candidate anode for commercialization of Na-ion batteries. Hard Carbon has a unique local atomic structure, which is composed of nanodomains of layered rumpled sheets that have short-range local order resembling graphene within each layer, but complete disorder along the c-axis between layers. A primary challenge holding back the development of Na-ion batteries is that a complete understanding of the structure–capacity correlations of Na-ion storage in Hard Carbon has remained elusive. This article presents two key discoveries: first, the characteristics of Hard Carbons structure can be modified systematically by heteroatom doping, and second, that these structural changes greatly affect Na-ion storage properties, which reveals the mechanisms for Na storage in Hard Carbon. Specifically, via P or S doping, the interlayer spacing is dilated, which extends the low-voltage plateau capacity, while increasing the defect concentrations with P or B doping leads to higher sloping sodiation capacity. The combined experimental studies and first principles calculations reveal that it is the Na-ion-defect binding that corresponds to the sloping capacity, while the Na intercalation between graphenic layers causes the low-potential plateau capacity. The understanding suggests a new design principle of Hard Carbon anode: more reversibly binding defects and dilated turbostratic domains, given that the specific surface area is maintained low.
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Hard Carbon anodes of sodium-ion batteries: undervalued rate capability
Chemical communications (Cambridge England), 2017Co-Authors: Zelang Jian, Xingfeng Wang, Ismael A. Rodríguez-pérez, Clement BommierAbstract:The rate capability of Hard Carbon has long been underestimated in prior studies that used Carbon/Na two-electrode half-cells. Through a three-electrode cell setup, we discover that it is the overpotential of the sodium counter electrode that drives the half-cells to the lower cutoff potential prematurely during Hard Carbon sodiation, particularly at high current rates, which prevents the Hard Carbon anode from being fully sodiated.
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High Capacity of Hard Carbon Anode in Na-Ion Batteries Unlocked by POx Doping
ACS Energy Letters, 2016Co-Authors: Todd Wesley Surta, Zelang Jian, William F. Stickle, Clement Bommier, Zhenyu Xing, Michelle R. Dolgos, Khalil AmineAbstract:The capacity of Hard Carbon anodes in Na-ion batteries rarely reaches values beyond 300 mAh/g. We report that doping POx into local structures of Hard Carbon increases its reversible capacity from 283 to 359 mAh/g. We confirm that the doped POx is redox inactive by X-ray adsorption near edge structure measurements, thus not contributing to the higher capacity. We observe two significant changes of Hard Carbon’s local structures caused by doping. First, the (002) d-spacing inside the turbostratic nanodomains is increased, revealed by both laboratory and synchrotron X-ray diffraction. Second, doping turns turbostratic nanodomains more defective along ab planes, indicated by neutron total scattering and the associated pair distribution function studies. The local structural changes of Hard Carbon are correlated to the higher capacity, where both the plateau and slope regions in the potential profiles are enhanced. Our study demonstrates that Na-ion storage in Hard Carbon heavily depends on Carbon local struc...
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Low-Surface-Area Hard Carbon Anode for Na-Ion Batteries via Graphene Oxide as a Dehydration Agent
ACS applied materials & interfaces, 2015Co-Authors: Wei Luo, Zelang Jian, Clement Bommier, Rich G. Carter, Sean Vail, Jong Jan LeeAbstract:Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, Hard Carbon is very attractive due to its high capacity and low cost. However, Hard Carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for Hard Carbon, can effectively reduce the specific surface area of Hard Carbon to as low as 5.4 m2/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burnoff of sucrose caramel over a wider temperature range. The obtained low-surface-area Hard Carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.
