• Journal of Electrochemical Science and Technology
• /
• 제13권1호
• /
• pp.32-53
• /
• 2022

Although lithium-ion batteries are currently the most reliable power supply system for various mobile applications, further improvement in energy density is still required as the need for batteries in large energy-consuming devices is rapidly growing. However, in the anode, the most widely commercialized graphite-based anode materials almost face theoretical limitations. In addition, sodium-ion batteries have been actively studied to replace expensive charge carriers with cheaper ones. Accordingly, conversion-based materials have been extensively studied as high-capacity anode materials in both lithiumion batteries and sodium-ion batteries because their theoretical capacity is twice or thrice higher than that of insertion-based materials. This review will provide a comprehensive understanding of conversion-based materials, including basic charge storage behaviors, critical drawbacks that should be overcome, and practical material design for high-performance.

• Journal of Electrochemical Science and Technology
• /
• 제10권1호
• /
• pp.1-13
• /
• 2019

Na-ion batteries are being considered as promising cost-effective energy storage devices for the future compared to Li-ion batteries owing to the crustal abundance of Na-ion. However, the large radius of the Na ion result in sluggish electrode kinetics that leads to poor electrochemical performance, which prohibits the use of these batteries in real time application. Therefore, identification and optimization of the anode, cathode, and electrolyte are essential for achieving high-performance Na-ion batteries. In this context, the current review discusses the suitable high-voltage cathode materials for Na-ion batteries. According to a recent research survey, sodium vanadium fluorophosphate (NVPF) compounds have been emphasized for use as a high-voltage Na-ion cathode material. Among the fluorophosphate groups, $Na_3V_2(PO_4)_2F_3$ exhibited the high theoretical capacity ($128mAh\;g^{-1}$) and working voltage (~3.9 V vs. $Na/Na^+$) compared to the other fluorophosphates and $Na_3V_2(PO_4)_3$. Here, we have also highlighted the classification of Fluorophosphates, NVPF composite with carbonaceous materials, the appropriate synthesis methods and how these methods can enhance the electrochemical performance. Finally, the recent developments in NVPF for the application in energy storage devices and its outlook are summarized.

• 한국세라믹학회지
• /
• 제53권4호
• /
• pp.406-410
• /
• 2016

Carbon-coated sodium iron pyrophosphate ($Na_2FeP_2O_7$) was prepared by a simple and low-cost pyro-synthesis route for further use as the cathode for Na-ion batteries. The X-ray diffraction (XRD) pattern of the sample annealed at $650^{\circ}C$ confirmed the pure triclinic phase of $Na_2FeP_2O_7$. Electron microscopy studies revealed a cross linked plate shape morphology of the $Na_2FeP_2O_7$ sample. When tested for application in Na-ion battery, the $Na_2FeP_2O_7$ cathode showed two redox pairs in the potential window of 2.0-4.0 V. The cathode registered initial discharge and charge capacities of 80.85 and 90 mAh/g, respectively, with good cycling performance.

• 전기화학회지
• /
• 제22권1호
• /
• pp.22-35
• /
• 2019

이차 전지의 개발이 전기자동차나 스마트그리드와 같은 중대형의 에너지저장장치로 응용범위가 확대됨에 따라 이차 전지의 경제성확보가 화두가 되고 있다. 나트륨이차전지는 리튬보다 훨씬 저렴한 나트륨원료를 사용하여 저가의 차세대 이차 전지로 크게 주목받고 있다. 이에 따라 이온 반경이 큰 나트륨이온의 삽입과 탈리를 원활하게 해줄 수 있는 음극 소재의 개발이 최근 몇 년간 활발히 수행되어 왔다. 나트륨이차전지용 음극은 세 가지의 반응 메커니즘 (층간 삽입반응, 금속-합금반응, 전환반응)을 기반한 소재들이 보고되었으며, 본 총설에서는 전환반응으로 구동하는 다양한 음극 소재들을 소개하며 나트륨 전지 셀 내 반응 메커니즘을 소개하고자 한다.

• 한국수소및신에너지학회논문집
• /
• 제27권6호
• /
• pp.753-763
• /
• 2016

High temperature sodium/sulfur battery(Na/S battery) has good electrochemical properties, but, the battery has some problems such as explosion and corrosion at al. because of using the liquid electrodes at high temperature and production of high corrosion. Room temperature sodium/sulfur batteries (NAS batteries) is developed to resolve of the battery problem. To recently, room temperature sodium/sulfur batteries has higher discharge capacity than its of lithium ion battery, however, cycle life of the battery is shorter. Because, the sulfur electrode and electrolyte have some problem such as polysulfide resolution in electrolyte and reaction of anode material and polysulfide. Cycle life of the battery is improved by decrease of polysulfide resolution in electrolyte and block of reaction between anode material and polysulfide. If room temperature sodium/sulfur batteries (NAS batteries) with low cost and high capacity improves cycle life, the batteries will be commercialized batteries for electric storage, electric vehicle, and mobile electric items.

• 한국분말재료학회지
• /
• 제30권5호
• /
• pp.387-393
• /
• 2023

Transition metal chalcogenides are promising cathode materials for next-generation battery systems, particularly sodium-ion batteries. Ni₃Co₆S₈-pitch-derived carbon composite microspheres with a yolk-shell structure (Ni₃Co₆S₈@C-YS) were synthesized through a three-step process: spray pyrolysis, pitch coating, and post-heat treatment process. Ni₃Co₆S₈@C-YS exhibited an impressive reversible capacity of 525.2 mA h g^-1 at a current density of 0.5 A g^-1 over 50 cycles when employed as an anode material for sodium-ion batteries. However, Ni₃Co₆S₈ yolk shell nanopowder (Ni₃Co₆S₈-YS) without pitch-derived carbon demonstrated a continuous decrease in capacity during charging and discharging. The superior sodium-ion storage properties of Ni₃Co₆S₈@C-YS were attributed to the pitch-derived carbon, which effectively adjusted the size and distribution of nanocrystals. The carbon-coated yolk-shell microspheres proposed here hold potential for various metal chalcogenide compounds and can be applied to various fields, including the energy storage field.

• 한국재료학회지
• /
• 제16권3호
• /
• pp.193-197
• /
• 2006

The sodium/sulfur(Na/S) battery has many advantages such as high theoretical specific energy(760Wh/kg), and low material cost based on the abundance of electrode material in the earth. It has been reported that the electrochemical properties of sodium/sulfur cell above $300^{\circ}C$, utilized a solid ceramic electrolyte and liquid sodium and sulfur electrodes. A lot of researches have been performed in this field. Recently, Na/S battery system was applied for electricity storage system for load-leveling. One of severe problems of sodium/sulfur battery was high operating temperature above $300^{\circ}C$, which could induce the explosion and corrosion by molten sodium, sulfur and polysulfides. In order to develop sodium battery operated at low temperature, sodium ion battery has been studied using carbon anode, and sodium oxides cathodes. However, the energy densities of the sodium ion batteries were much lower than high temperature sodium/sulfur cell. In this study, the sodium/sulfur battery with 1M $NaCF_3SO_3$ is tested at room temperature. The charge-discharge mechanism was discussed based on XRD, DSC, SEM and EDS results.

• 전기화학회지
• /
• 제18권4호
• /
• pp.161-171
• /
• 2015

수열합성법을 이용하여 $Zn_2GeO_4$ 및 $Zn_2SnO_4$ 나노선을 대량 합성하였고 리튬이온 전지와 소듐이온전지의 전기화학적 특성을 조사하였다. 리튬이온전지에서 $Zn_2GeO_4$ 나노선은 50 사이클 이후에 1021 mAh/g, $Zn_2SnO_4$ 나노선은 692 mAh/g의 높은 방전용량을 갖는 것을 확인하였고 두 나노선 모두 98%가 넘는 쿨롱 효율을 보였다. 따라서 이들 나노선은 고성능 리튬이온전지의 개발을 위한 음극소재로 기대된다. 또한 소듐이온전지에 대한 관심이 국내는 물론 전 세계적으로 집중이 되고 있어 처음으로 $Zn_2GeO_4$과 $Zn_2SnO_4$ 나노선에 대한 소듐이온전지를 제작하여 용량을 측정하였다. 측정한 결과 이들 나노선은 50 사이클 이후에 각각 168 mAh/g 과 200 mAh/g의 방전용량을 갖는 것을 확인하였고 두 나노선 모두 97%가 넘는 높은 쿨롱 효율을 보였으며 이에 우리의 첫 시도가 앞으로 많은 연구에 기여할 것으로 예상한다.

• Current Applied Physics
• /
• 제18권11호
• /
• pp.1431-1435
• /
• 2018

Using first-principles calculations, we successfully investigate the electrochemical performance of the monoclinic $NaMnO_2$ for the sodium ion batteries. $NaMnO_2$ possesses a voltage window of 3.54-2.52 V and theoretical reversible capacity of $136mAh\;g^{-1}$. Besides, we find that the metallicity of the monoclinic $NaMnO_2$ gradually increases during Na extraction. Moreover, the computational Na migration energy barrier in the monoclinic $NaMnO_2$ is 0.18 eV, ensuring ideal conductivity and reversible capacity. Although the Jahn-Teller distortion effects limit the enhancement of the reversible capacity of the monoclinic $NaMnO_2$, it is still a right cathode material for the sodium ion batteries. The computational results are well in consistent with the experimental investigations.

• 전자통신동향분석
• /
• 제38권5호
• /
• pp.90-99
• /
• 2023

Recently, with the trend of information technology convergence and electrification, batteries are being widely used in fields such as industry, transportation, and specific applications. By 2030, the secondary battery market is expected to grow explosively by more than eight times compared with 2020 to $351.7 billion owing to the expanding adoption of electric vehicles. Depending on the electrochemical reactions in the electrode, a primary battery can only discharge through an irreversible reaction, while a secondary battery can be repeatedly charged and discharged using reversible reactions. According to the type of charge carrier ions, secondary batteries may be classified into those made of lithium, sodium, potassium, magnesium, and aluminum ions. We analyze the current status and technological issues of lithium-ion batteries, lithium-sulfur batteries, and solid-state batteries, which are representative examples of lithium secondary batteries. In addition, research trends in lithium secondary batteries are discussed.