The integration of high-capacity active materials onto flexible substrates is essential for advancing flexible sodium-ion batteries (SIBs). Herein, we report a novel strategy for fabricating high-performance, flexible SIB anodes via the immobilization of molybdenum disulfide ( MoS2) nanoparticles on carbon cloth (CC) modified with metal–organic framework-derived carbon nanotubes (MOF-derived CNTs). In this method, Co-containing zeolitic imidazolate frameworks (ZIFs) were assembled on polyaniline-coated CC, followed by CNT growth via chemical vapor deposition (CVD) and hydrothermal deposition of MoS2. The resulting MoS2@ CNT@CC electrodes achieved significantly higher MoS2 loading (15–20 wt%) compared to direct deposition on CC (< 5 wt%). Electrochemical evaluation revealed an initial discharge capacity of 231 mAh g− 1 with a Coulombic efficiency of 94.3%, outperforming MoS2@ CC (150 mAh g− 1, 77.8%) and bare CC (113 mAh g− 1, 74.3%). After 100 cycles at 50 mA g− 1, MoS2@ CNT@CC maintained a stable capacity of 133 mAh g− 1 and an average Coulombic efficiency of 99.9%. Cyclic voltammetry confirmed enhanced redox activity, while mechanical tests showed no significant degradation after 10,000 bending cycles (10 mm radius). These findings highlight the effectiveness of MOF-derived CNTs in enhancing MoS2 loading, conductivity, and mechanical resilience, offering a promising route toward robust and efficient flexible SIB anodes.

This study was conducted to examine the structural stability of a lightweight structure for a sliding-type battery rack system located under an electric bus. To address the shortcomings of the existing sliding battery rack systems, the battery rack system was designed by applying lightweight materials and utilizing a bolt-mounting connection type. Finite Element Method(FEM)-based structural analysis was performed, considering both the system’s self-weight and the weight of the installed batteries. The analysis identified the maximum stress value and its location within the entire system. Furthermore, considering the different materials used in various components, the maximum stress values for each component were individually derived. By comparing the maximum stress with the yield strength of each material, it was confirmed that the designed lightweight battery rack system had secured structural stability.

본 연구에서는 과불화 알킬 사슬이 도입된 산화 그래핀(perfluoroalkyl-grafted graphene oxide, FGO)을 합성하고, 이를 과불소화계 고분자인 나피온(Nafion)에 복합화하여 바나듐 레독스 흐름 전지(vanadium redox flow battery, VRFB)용 이 온 교환 막을 개발하고자 하였다. FGO는 염기성 촉매 하에서 카르복실산기를 함유한 폴리(헥사플루오로프로필렌 옥사이드) (157 FSL, DuPont)의 카르복실산기와 GO의 에폭시기 간 개환 에스터화 반응을 통해 합성하였다. 합성된 FGO를 Nafion 기 지체에 함량을 달리하여 첨가한 복합막(N/FGO_X)을 제조하고, 함수율, 체적 안정성, 수소 이온 전도도, 바나듐 이온 투과도 및 셀 성능을 평가하였다. N/FGO 복합막은 Nafion 단일막 대비 낮은 함수율과 체적 변화율을 보였으며, FGO의 물리적 차단 효과에 의해 바나듐 이온 투과도가 감소하면서도 수소 이온 전도도를 유지하여 우수한 이온 선택도를 나타내었다. VRFB 단 위 셀 평가 결과, FGO가 도입된 복합막은 Nafion 단일막을 적용한 셀 대비 높은 방전 용량, 쿨롱 효율 및 에너지 효율을 유 지하였다.

Bamboo charcoal has high ecological and economic value, and is a sustainable and valuable resource for the development of advanced materials such as supercapacitors and batteries. The carbon content in bamboo-based white charcoal produced in traditional Korean kiln reaches 100% when the charcoals heat treated up to 2400℃. X-ray diffraction shows that graphite begins to form at 1500℃, becomes more pronounced at 1800℃, and crystallizes into a dense turbostratic structure at 2000℃. At 2400℃, discrete graphite peaks are confirmed in d002 and d100 planes, while carbon isotope peaks disappear. Raman spectroscopy shows that graphite crystals form at 1800℃, as indicated by a clear 2D band at 2680 cm⁻1. At 2400℃, the height of the D band at 1350 cm⁻1 is lower than that of the G band at 1580 cm⁻1, indicating a high degree of graphitization. The isothermal nitrogen adsorption–desorption curves show that the monolayer value of the sample decreases up to 1300℃, accompanied by a low-pressure hysteresis phenomenon. When heat-treated at 1500℃ or higher, this phenomenon disappears and the monolayer value decreases significantly, indicating the disappearance of micropores and occurrence of graphitization. After 10 min. of heat treatment at 2400℃, the specific surface area of the graphitized charcoal becomes 8.45 m2/ g, similar to that of artificial graphite, which shows promising results of 217 mAh/g at a current density of 0.02 A/g for using in Lithium ion battery electrode.

The insulating nature of elemental sulfur has been regarded as a major challenge limiting the electrochemical performance of Li–S batteries. Consequently, previous efforts have focused on developing conductive porous materials to enhance sulfur contact. In this study, we review this conventional assumption and demonstrate that the insulating property of sulfur is not the primary factor affecting Li–S battery performance. Instead, we introduce a novel sulfur host design using polar mesoporous carbon (p-MC), which possesses ultra-low electrical conductivity (6.45 × 10− 7 S cm− 1) and functional groups. Our results demonstrate that all sulfur particles within the nearly insulating p-MC matrix actively participate in electrochemical reduction during the initial discharge. A comparative study with a nonpolar mesoporous carbon host, which features a similar porous structure but higher conductivity (1.07 × 10− 1 S cm− 1), showed that the p-MC host achieved superior cycling stability. This performance is attributed to the strong interaction between the polar functional groups of p-MC and lithium polysulfides, enabling effective and stable confinement of the active materials during cycling. Our findings highlight a paradigm shift in the design of sulfur host materials and the critical role of polar functionalities. This study offers a promising strategy for the development of durable and high-performance Li–S batteries.

This study presents the results of compression, drop impact, and vibration durability analyses conducted to evaluate the mechanical reliability of Battery Pack Cases (BPCs) in electric vehicle (EV) systems. BPCs are essential structural components that must endure compressive loads, impact forces, and vibrational fatigue. Finite Element Analysis (FEA) was applied to a representative BPC model to assess deformation, impact resistance, and vibration endurance. The results indicate that the BPC maintained integrity within yield strength limits under compressive loading and effectively absorbed energy under drop impact. Furthermore, Power Spectral Density (PSD) analysis identified stress concentration regions, providing insights for structural optimization. Overall, the findings support the development of lightweight and reliable BPC designs for advanced EV applications.

This study presents a non-invasive method for current estimation using the voltage drop across automotive MICRO-2 fuses. Unlike conventional techniques that require additional hardware, the proposed approach utilizes the inherent milliohm-level resistance of fuses, enabling current monitoring without circuit modification. Experiments were performed on 7.5[A] A fuses to analyze resistance variations with rating, temperature, and contact position. Based on these results, a current estimation model with temperature and tolerance correction was developed. Validation showed that the optimized resistance model (Ropt) achieved the lowest error (MAE: 0.0197 A, MAPE: 0.84%), demonstrating the feasibility of fuse-based current sensing for real vehicle applications and leakage current diagnostics.

In this study, composite pouch films incorporating ionite were fabricated, and their structural properties as well as temperature variations during charge–discharge cycles were evaluated to examine their applicability as heat-suppression pouch films for secondary batteries. The films were prepared using a film coater (Coretech, CT-AF300), with variations in ionite content and particle size. In addition, the effects of plasma treatment on the surface state of PET films were investigated to enhance coating adhesion, with the aim of determining the optimal fabrication conditions. Furthermore, an infrared thermal imaging camera and a custom-built test device were employed to measure the temperature differences with and without the pouch films during charge– discharge processes, thereby assessing the potential of developing next-generation high-performance pouch films.

All-vanadium redox flow battery (VRFB) has been considered as a promising candidate for the construction of renewable energy storage system. Expanded graphite possesses immense potential for use as typical bipolar plates in VRFB stacks. Nevertheless, the pure expanded graphite bipolar plates suffer from severe swelling in electrolyte, resulting in the losses of mechanical stability and electrical conductivity, thus leading to the efficiency decay within several cycles. Herein, we present a “nanoglue” strategy for tuning the structure/surface properties of expanded graphite by employing polyvinylidene fluoride (PVDF) polymer as structural sealant. Such PVDF “nanoglue” on expanded graphite results in the fine-repairment toward the surface microcracks and cross-section edges, which is beneficial to suppress the electrolyte permeation and improve the anti-swelling capacity. Moreover, it has been found that the PVDF “nanoglue” can improve the flexibility, allowing for the fabrication of ultrathin bipolar plates (0.67 mm) with low electrical resistivity. Benefiting from these integrated characteristics, the VRFB employing the as-fabricated composite bipolar plates delivers excellent cyclic efficiencies (voltage efficiency, coulombic efficiency, and energy efficiency) and ultralow ohmic voltage loss of less than 1.1 mV (< 0.1% of the VRFB rated voltage of 1.25 V) at a high current density of 200 mA cm− 2.

온실가스 배출을 줄이기 위해 기존 선박에 사용되는 내연기관을 대체할 수 있는 다양한 기술이 제안되고 있으며, 그중에서도 고 효율·무배출 특성을 가진 연료전지가 유망한 대안으로 주목받고 있다. 본 연구에서는 선박의 종류 및 규모에 따라 네 가지 유형의 선박을 선정하고, 기존 내연기관 기반 추진 시스템을 연료전지-배터리 하이브리드 추진 시스템으로 전환하는 방안을 검토하였다. 제안된 하이브리 드 추진 시스템은 주 전원으로 고분자전해질막연료전지(PEMFC), 보조 전원으로 Battery를 사용한다. PEMFC가 기본 부하(base load)를 담당하 고, Battery는 피크 부하(peak load)를 담당한다. PEMFC는 50kW 스택을 기본 단위로 모듈화하여 적용하였으며, 시스템 전체 크기, 연료전지와 배터리의 비율, 주변 기기와의 연계 등을 고려하여 각 선박 유형에 적합한 시스템 구성을 도출하였다. 연구 결과, 선박의 종류와 운항 특성 에 따라 PEMFC-Battery hybrid propulsion system의 구성이 달라져야 함을 확인하였다. 항해가 길어질수록 PEMFC의 비중을 높이는 것이 필요 하며 액화수소의 사용이 강제화된다. 또한 항해 구역과 긴급 상황에 대응할 수 있도록 시스템의 단일/이중화 여부 또한 고려되어야 한다. 선 박 규모에 따라 적정한 추진 전동기와 주변 기기 설치를 고려해야 한다. 이러한 운항 조건과 설계 요소를 반영한 PEMFC-Battery hybrid propulsion system은 다가오는 배출 규제를 충족할 수 있으며, 해양 분야 탈탄소화를 위한 실현 가능한 대안이 될 수 있다.

In this study, the shape of the exterior, not the inside of the product, was modified. Various exterior shape change plans were compared and reviewed through injection molding analysis, and among them, the most effective shape for suppressing warpage deformation was derived. The shape of the product was modified to optimize the bending deformation of the cover located at the top of the automobile battery case. The analysis was conducted under a total of three conditions, each of shape A, which is a rectangular parallelepiped shape at the top of the product, and shape B, which is concave on the side of the product. As a result of the study, both shape A and shape B were reduced compared to the amount of bending deformation of the original shape. Among them, shape B2, which showed the largest reduction, decreased by 82.096% from the amount of bending deformation of the original shape.

Manganese dioxide, functioning as a cathode material for aqueous zinc-ion batteries (AZIBs), demonstrates a variety of benefits, such as elevated theoretical specific capacity, outstanding electrochemical performance, environmental compatibility, ample resource availability, and facile modification. These advantages make MnO2 one of the cathode materials that have attracted much attention for AZIBs. Nevertheless, manganese dioxide cathode in practical applications suffers from structural instability during the cycling process because of sluggish electrochemical kinetics and volume expansion, which hinder their large-scale application. Doping and compositing with conducting frameworks is an effective strategy for improving structural stability. Herein, homogeneously in situ growth of Yttrium-doped MnO2 nanorods on conductive reduced graphene oxide (Y-MnO2/rGO), were synthesized through a straightforward hydrothermal method. The Y-MnO2/rGO electrodes have an ultra-long cycle life of 179.2 mA h g− 1 after 2000 cycles at 1 A g− 1 without degradation. The excellent structural stability is attributed to the cooperative effect of yttrium doping and compositing with rGO, which is an effective approach to enhance the stability and mitigate the Jahn–Teller distortion associated with Mn ions.

본 연구는 중국의 선도적인 이차 전지 기업인 CATL을 사례로 하여, 기술 혁신 능력의 발전 과정을 기술 격차, 기술 효율, 기술 축적의 세 가지 핵심 차원을 중심으로 분석하는 데 목적이 있다. 특히 2011년부터 2024년까지의 연차 보고서, 언론 보도, 산업 자료 등을 바탕으로, CATL 의 기술 진화 경로를 모방 - 창조적 모방 - 자주 혁신이라는 세 단계로 구분하고, 각 단계에서 외부 환경과 기술 역량 간의 상호작용을 동적 능 력 이론 틀 내에서 고찰하였다. 또한 본 연구는 구매자, 공급자, 경쟁자, 정부, 기술이라는 외부 환경 요소와 기술 혁신의 내생적 요인 간 통합 모델을 구성하고, 그 분석을 통해 CATL이 기술 격차 축소, 효율 향상, 기술 축적을 어떻게 실현하였는지를 규명하였다. 본 연구는 CATL의 사 례를 통해 급변하는 글로벌 배터리 산업에서 기술 후발 기업이 어떻게 전략적으로 대응하고 성장할 수 있는지를 보여주며, 향후 한국을 포함한 타 국가의 유사 산업 및 기업에 실질적인 시사점을 제공한다.

환경 문제가 대두되면서 전기자동차에 대한 수요가 증가하게 되고, 이에 따라 폐배터리 처리 기술이 각광받고 있다. 폐배터리를 재 활용하는 대신 재사용하기 위해서는 배터리 성능 검증 기술의 중요성도 커지고 있다. 배터리 성능 검증 기술은 시간을 단축하는 동시 에 정확도를 높이는 데 집중해야 한다. 본 논문에서는 배터리 전기화학 분광법을 활용해 배터리 방전 전압 그래프를 얻고 배터리 성능 을 예측하는 다중물리 분석을 활용하고자 한다. 본 논문에서는 임피던스 매칭 기법을 활용해 배터리 방전 특성을 제어하고 이를 통해 방전 그래프를 얻는 기법을 제안한다. 제안하는 기법에서는 배터리를 실제로 완전 충전 및 방전하지 않고 단시간 동안 임피던스만 측 정해 전압 곡선 데이터를 추출한다. 이를 검증하기 위해 실제 데이터와 분석 데이터의 매칭을 수행했다. 이러한 접근 방식은 배터리 성능을 예측하고 최적화하는 데 적용될 수 있으며, 향후 에너지 저장 시스템의 설계 및 운영 최적화에 기여할 것으로 기대된다.

The high-rate performance of lithium/fluorinated carbon (Li/CFx) battery remains a challenge due to poor discharge dynamics behavior accompanied by the overheating issue. We developed a novel fluorinated reed-carbon with three-dimensional (3D) porous channels to favor discharge dynamics behavior achieving excellent discharge performance as high as 5 C. Typically, the preparation of fluorinated reed-carbon mainly involves three steps, namely, crushing into powders, pre-carbonization of reed and precise fluorination. During the fluorination process, we precisely controlled the fluorination temperature in range of 330–370 °C and gas ratio ( F2 of ~ 15 vol%) to optimize the fluorine carbon ratio. This kind of CFx possesses the novel structure at the scale of micron level ranging from 0.5 to 3 μm, which favors the electrolyte and charge transport through the channels smoothly. This 3D porous structure increases the specific surface area of the CFx material, providing more chemical reaction sites to enhance discharge dynamics behavior and effectively hinder the volume expansion of batteries, which is conductive to improve the high-rate performance of Li/CFx battery. This low-cost and facile approach opens up a novel pathway to design carbon materials and CFx for Li/CFx battery.

This paper presents an 2 kW commercial Li-ion(lithium-ion) battery model using PSIM simulation. An in-house designed transformer was employed to measure the leakage and magnetic inductance and determine the resonant frequency. The LLC resonant converter’s transfer function was derived using the FHA method, and voltage gain characteristics were analyzed concerning frequency, Q factor, and inductance variations. The CC-CV charge mode was evaluated at different C-rates, targeting the charging voltage for e-bikes. The results demonstrated that battery voltage increased with SOC until reaching the final charging voltage.

리튬이온배터리는 높은 에너지 저장 효율과 환경 지속 가능성으로 점점 더 많은 관심을 받고 있다. PU 기반 리튬이온배터리에 사용되는 기존의 고분자 (polyurethane, PU) 바인더는 높은 유연성과 기 계적 강도를 제공하여 전극의 부피 변화를 감소시키고 구조적 안정성을 확보하는데 효과적이지만, 이와같 은 고분자 계열의 바인더는 전기전도도가 낮고 생산 및 폐기 과정에서 환경 문제를 야기할 수 있다. 따라 서, 본 연구에서는 이러한 고분자계 바인더의 단점을 해결하고자 고분자계 바인더로 많이 사용되는 PU 기 반 리튬이온배터리에 비해 향상된 전기화학적 성능과 안정성을 가진 새로운 바인더로서 석유계 피치 (SM260)/고분자 (polyurethane, PU) 복합소재 기반 바인더를 개발하였다. 특히, PU 바인더가 적용된 리튬 이온배터리는 100 사이클 후 가역 용량이 80 mAh/g으로, 초기 용량의 25%의 용량 유지율을 나타낸 반면, 본 연구에서 개발한 석유계 피치 (SM260)/고분자 (polyurethane, PU) 복합소재 복합 바인더가 적용된 리 튬이온배터리는 100 사이클 후 가역용량이 208 mAh/g으로 유지되고, 초기 용량의 68% 용량 유지율을 나 타내었다.

To analyze the effect of fire in electric-vehicle battery on concrete cement structure. A scenario evaluation was conducted for fire occurrence due to external influences on lithium battery cells used in electric vehicles. Visual inspection was conducted at each stage of the battery fire, and the fire duration and temperature were measured. The battery temperature rise curve and temperature during fire have been examined previously. The stability of a cement structure was evaluated via X-ray diffraction and SEM analyses of the reaction-product changes with respect to temperature. The battery temperature rise curve shows that the battery begins to change at 200 °C–300 °C. However, the general stage of battery damage cannot be readily confirmed from the literature. The current experiment and literature review indicate that battery fire can cause the fire temperature to increase beyond 1000 °C within a few seconds. The reaction product changes structurally in cement from 300 °C or higher. Many voids are generated owing to the decomposition of Ca(OH)2 and C-S-H gel. The temperature of an electric-vehicle fire increases rapidly to 1000 °C or higher within a few seconds. High temperatures change the reaction products in cement structures, thus creating internal voids and cracks and reducing the stability of the structure; therefore, the appropriate countermeasures must be identified.