TiN Anode for Electrolytic Reduction of UO2 in Pyroprocessing

Sung-Wook Kim,Eun-Young Choi,Wooshin Park,Hun Suk Im,Jin-Mok Hur 한국방사성폐기물학회 2015 방사성폐기물학회지 Vol.13 No.3

파이로프로세싱 전해환원 공정에서 현재 사용 중인 Pt 양극을 대체하기 위한 소재 개발은 매우 중요하다. 이 연구에서는 전 기화학 반응시 산소를 발생시키는 전도성 세라믹 양극으로서 TiN의 전기화학적 거동을 알아보았다. UO2의 전해환원이 일어 나는 동안 TiN 양극의 적합성과 안정성에 대한 평가를 진행하였다. LiCl-Li2O 용융염에서 TiN 양극을 이용하여 UO2를 전기 화학적으로 금속 U로 변환시킬 수 있었다. 반응 도중 TiN의 산화 반응은 관찰되지 않았다. 하지만 TiN 내부에서 공공이 생 기는 것을 확인하였으며, 이에 따라 소재 수명에 제한이 있을 것으로 판단된다. Developing novel anode materials to replace the Pt anode currently used in electrolytic reduction is an important issue on pyroprocessing. In this study, the electrochemical behavior of TiN was investigated as the conductive ceramic anode which evolves O2 gas during the reaction. The feasibility and stability of the TiN anode was examined during the electrolytic reduction of UO2. The TiN anode could electrochemically convert UO2 to metallic U in a LiCl–Li2O molten salt electrolyte. No oxidation of TiN was observed during the reaction; however, the formation of voids in the bulk section appeared to limit the lifetime of the TiN anode.

TiN 양극을 이용한 파이로프로세싱 UO2 전해환원

김성욱,최은영,박우신,임현숙,허진목 한국방사성폐기물학회 2015 방사성폐기물학회지 Vol.13 No.3

파이로프로세싱 전해환원 공정에서 현재 사용 중인 Pt 양극을 대체하기 위한 소재 개발은 매우 중요하다. 이 연구에서는 전 기화학 반응시 산소를 발생시키는 전도성 세라믹 양극으로서 TiN의 전기화학적 거동을 알아보았다. UO2의 전해환원이 일어 나는 동안 TiN 양극의 적합성과 안정성에 대한 평가를 진행하였다. LiCl-Li2O 용융염에서 TiN 양극을 이용하여 UO2를 전기 화학적으로 금속 U로 변환시킬 수 있었다. 반응 도중 TiN의 산화 반응은 관찰되지 않았다. 하지만 TiN 내부에서 공공이 생 기는 것을 확인하였으며, 이에 따라 소재 수명에 제한이 있을 것으로 판단된다. Developing novel anode materials to replace the Pt anode currently used in electrolytic reduction is an important issue on pyroprocessing. In this study, the electrochemical behavior of TiN was investigated as the conductive ceramic anode which evolves O2 gas during the reaction. The feasibility and stability of the TiN anode was examined during the electrolytic reduction of UO2. The TiN anode could electrochemically convert UO2 to metallic U in a LiCl–Li2O molten salt electrolyte. No oxidation of TiN was observed during the reaction; however, the formation of voids in the bulk section appeared to limit the lifetime of the TiN anode.

나노 구조를 가지는 다공성 주석 산화물의 전기화학적 특성

이재욱,박수진,신헌철,Lee, Jae-Wook,Park, Su-Jin,Shin, Heon-Cheol 한국재료학회 2011 한국재료학회지 Vol.21 No.1

A nano-porous structure of tin oxide was prepared using an anodic oxidation process and the sample's electrochemical properties were evaluated for application as an anode in a rechargeable lithium battery. Microscopic images of the as-anodized sample indicated that it has a nano-porous structure with an average pore size of several tens of nanometers and a pore wall size of about 10 nanometers; the structural/compositional analyses proved that it is amorphous stannous oxide (SnO). The powder form of the as-anodized specimen was satisfactorily lithiated and delithiated as the anode in a lithium battery. Furthermore, it showed high initial reversible capacity and superior rate performance when compared to previous fabrication attempts. Its excellent electrode performance is probably due to the effective alleviation of strain arising from a cycling-induced large volume change and the short diffusion length of lithium through the nano-structured sample. To further enhance the rate performance, the attempt was made to create porous tin oxide film on copper substrate by anodizing the electrodeposited tin. Nevertheless, the full anodization of tin film on a copper substrate led to the mechanical disintegration of the anodic tin oxide, due most likely to the vigorous gas evolution and the surface oxidation of copper substrate. The adhesion of anodic tin oxide to the substrate, together with the initial reversibility and cycling stability, needs to be further improved for its application to high-power electrode materials in lithium batteries.

TiN Anode for Electrolytic Reduction of UO2 in Pyroprocessing

김성욱,최은영,박우신,임현숙,허진목 한국방사성폐기물학회 2015 방사성폐기물학회지 Vol.13 No.3

Developing novel anode materials to replace the Pt anode currently used in electrolytic reduction is an important issue on pyroprocessing. In this study, the electrochemical behavior of TiN was investigated as the conductive ceramic anode which evolves O2 gas during the reaction. The feasibility and stability of the TiN anode was examined during the electrolytic reduction of UO2. The TiN anode could electrochemically convert UO2 to metallic U in a LiCl–Li2O molten salt electrolyte. No oxidation of TiN was observed during the reaction; however, the formation of voids in the bulk section appeared to limit the lifetime of the TiN anode.

액중 전기선 폭발법을 이용한 비정질 탄소가 코팅된 주석 나노분말의 제조 및 전기화학적 특성

김유영,송주석,조권구,Kim, Yoo-Young,Song, Ju-Suck,Cho, Kwon-Koo 한국분말야금학회 2016 한국분말재료학회지 (KPMI) Vol.23 No.4

Tin is one of the most promising anode materials for next-generation lithium-ion batteries with a high energy density. However, the commercialization of tin-based anodes is still hindered due to the large volume change (over 260%) upon lithiation/delithiation cycling. To solve the problem, many efforts have been focused on enhancing structural stability of tin particles in electrodes. In this work, we synthesize tin nano-powders with an amorphous carbon layer on the surface and surroundings of the powder by electrical wire explosion in alcohol-based liquid media at room temperature. The morphology and microstructures of the powders are characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The electrochemical properties of the powder for use as an anode material for lithium-ion battery are evaluated by cyclic voltammetry and a galvanometric discharge-charge method. It is shown that the carbon-coated tin nano-powders prepared in hexanol media exhibit a high initial charge specific capacity of 902 mAh/g and a high capacity retention of 89% after 50 cycles.

볼 밀링으로 제조된 리튬이온전지용 주석-흑연 복합체 음극재의 전기화학적 특성

이태희,홍현아,조권구,김유영 한국분말재료학회(구 한국분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.6

Tin/graphite composites are prepared as anode materials for Li-ion batteries using a dry ball-milling process. The main experimental variables in this work are the ball milling time (0–8 h) and composition ratio (tin:graphite=5:95, 15:85, and 30:70 w/w) of graphite and tin powder. For comparison, a tin/graphite composite is prepared using wet ball milling. The morphology and structure of the different tin/graphite composites are investigated using X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and scanning and transmission electron microscopy. The electrochemical properties of the samples are also examined. The optimal dry ball milling time for the uniform mixing of graphite and tin is 6 h in a graphite-30wt.%Sn sample. The electrode prepared from the composite that is dry-ballmilled for 6 h exhibits the best cycle performance (discharge capacity after 50th cycle: 308 mAh/g and capacity retention: 46%). The discharge capacity after the 50th cycle is approximately 112 mAh/g, higher than that when the electrode is composed of only graphite (196 mAh/g after 50th cycle). This result indicates that it is possible to manufacture a tin/graphite composite anode material that can effectively buffer the volume change that occurs during cycling, even using a simple dry ball-milling process.

<i>In operando</i> X-ray diffraction strain measurement in Ni₃Sn₂ – Coated inverse opal nanoscaffold anodes for Li-ion batteries

Glazer, Matthew P.B.,Wang, Junjie,Cho, Jiung,Almer, Jonathan D.,Okasinski, John S.,Braun, Paul V.,Dunand, David C. Elsevier 2017 Journal of Power Sources Vol.367 No.-

<P><B>Abstract</B></P> <P>Volume changes associated with the (de)lithiation of a nanostructured Ni<SUB>3</SUB>Sn<SUB>2</SUB> coated nickel inverse opal scaffold anode create mismatch stresses and strains between the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode material and its mechanically supporting Ni scaffold. Using <I>in operando</I> synchrotron x-ray diffraction measurements, elastic strains in the Ni scaffold are determined during cyclic (dis)charging of the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode. These strains are characterized using both the center position of the Ni diffraction peaks, to quantify the average strain, and the peak breadth, which describes the distribution of strain in the measured volume. Upon lithiation (half-cell discharging) or delithiation (half-cell charging), compressive strains and peak breadth linearly increase or decrease, respectively, with charge. The evolution of the average strains and peak breadths suggests that some irreversible plastic deformation and/or delamination occurs during cycling, which can result in capacity fade in the anode. The strain behavior associated with cycling of the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode is similar to that observed in recent studies on a Ni inverse-opal supported amorphous Si anode and demonstrates that the (de)lithiation-induced deformation and damage mechanisms are likely equivalent in both anodes, even though the magnitude of mismatch strain in the Ni<SUB>3</SUB>Sn<SUB>2</SUB> is lower due to the lower (de)lithiation-induced contraction/expansion.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lithiation-induced strains quantified in a Ni<SUB>3</SUB>Sn<SUB>2</SUB> inverse opal anode <I>in operando</I>. </LI> <LI> Lithiation induces compressive average strains in Ni inverse opal scaffold. </LI> <LI> Ni inverse opal scaffold strain distribution reversibly broadens upon lithiation. </LI> <LI> Three measured volumes show similar cyclic strain averages and distributions. </LI> <LI> Ni<SUB>3</SUB>Sn<SUB>2</SUB> measured cyclic strains are similar to prior Si inverse opal anode studies. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

수열 합성법에 의해 제조된 주석-안티몬 황화물계 나노복합체 기반 나트륨이온전지용 음극의 전기화학적 특성

박소현,정수환,엄수윤,이상준,김주형 한국재료학회 2022 한국재료학회지 Vol.32 No.12

Tin-antimony sulfide nanocomposites were prepared via hydrothermal synthesis and a N2 reduction process for use as a negative electrode in a sodium ion battery. The electrochemical energy storage performance of the battery was analyzed according to the tin-antimony composition. The optimized sulfides exhibited superior charge/discharge capacity (770 mAh g-1 at a current density of 100 mA g-1) and stable lifespan characteristics (71.2 % after 200 cycles at a current density of 500 mA g-1). It exhibited a reversible characteristic, continuously participating in the charge-discharge process. The improved electrochemical energy storage performance and cycle stability was attributed to the small particle size, by controlling the composition of the tin-antimony sulfide. By optimizing the tin-antimony ratio during the synthesis process, it did not deviate from the solubility limit. Graphene oxide also acts to suppress volume expansion during reversible electrochemical reaction. Based on these results, tin-antimony sulfide is considered a promising anode material for a sodium ion battery used as a medium-to-large energy storage source.

Metastable tin oxide electrode for efficient electrochemical CO₂ Reduction to formate

장정환,정주원,강진수,성영은 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Electrochemical reduction of carbon dioxide is promising way to convert Carbon dioxide into valuable products. Among these products, formate is economically viable due to its simple reaction pathway and relatively high energy value. Therefore, tin-based materials have received attention as they show high performance in formate production. In this work, we synthesized metastable tin oxide electrode by anodization and thermal annealing. Tin oxide electrode enhances its electrochemical double layer capacitance by anodization and becomes highly crystalline after thermal annealing. Electrochemical measurements show its high faradaic efficiency of 60% for CO₂ reduction to formate at -0.8 V. It also exhibits a excellent formate partial current density of 33.66mA/㎠. According to various spectroscopic analyses, tin oxide remains its metastable SnO₂ phase at quite reductive potential of -0.8 V due to its cyrstalline structure by thermal annealing.

Study of tin-sulphur-carbon nanocomposites based on electrically exploded tin as anode for sodium battery

Pervez, S.A.,Kim, D.,Lee, S.M.,Doh, C.H.,Lee, S.,Farooq, U.,Saleem, M. Elsevier Sequoia 2016 Journal of Power Sources Vol.315 No.-

An electrochemical study of tin-sulphur-carbon nano-composites, based on electrically exploded tin-carbon nanoparticles as anode for sodium-ion battery (NIB), is carried out in electrolytes with and without fluoroethylene carbonate (FEC). The composites are synthesized through high energy mechanical milling (HEMM) of electrical exploded tin, sulphur nanoparticles and grinded carbon. The final product consists of tin sulfide nanoparticles embedded in amorphous carbon matrix. The results demonstrate an excellent response for the electrode materials in terms of initial discharge capacity (>425 mAhg<SUP>-1</SUP>) and cyclic performance (415 mAhg<SUP>-1</SUP> after 50 cycles). Even more remarkably, at high current densities of 400, 600, and 800 mAg<SUP>-1</SUP>, electrodes still offer specific capacities of about 375, 355, and 315 mAhg<SUP>-1</SUP>, respectively, suggesting good rate capability of the materials. Furthermore, it is observed that the material response is much better when electrolyte has FEC as an additive which helped in the formation of an optimized SEI layer. Such an improved electrochemical performance of the electrode materials highlights their suitability for the recently emerging Na-ion battery technology.