共查询到20条相似文献,搜索用时 56 毫秒
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先进锂离子电池的发展需要更高性能的电池材料或更优化的电池结构,深入了解电池材料的老化衰减机理是提高电池性能的前提。原位光学显微镜方法具有操作简便、原位反应池模拟环境真实,以及从介观到宏观的大范围尺度进行表征的特点,是目前最适合开展原位研究的表征方法。本文综述了原位光学显微镜方法在锂离子电池材料老化衰减方面的研究进展,介绍了原位光学显微镜方法中原位反应池的典型结构,阐述了该方法应用于锂离子浓度及其分布、析锂、电池材料体积膨胀与开裂和应力应变演化等方面的研究进展。最后,提出了原位光学显微镜方法在光学显微镜分辨率、原位反应池功能性、多表征方法联用以及先进图像处理和分析方法等方面的未来关注方向。 相似文献
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锂离子电池低温存储技术是智慧城市发展的关键之一。商用电解液在低温下易凝固、阻抗高限制了锂离子电池的进一步应用。因此电解液的优化成为改善锂离子电池低温性能的研究热点之一。本文介绍了低温电解液的研究进展。综述了温度对锂离子电池充放电影响,提出电解液改性是提高锂离子电池低温性能的关键。低温电解液的改性主要包括锂盐、溶剂和添加剂等方面,并对锂离子电池低温性能的下一步研究进行了展望。低温电解液锂盐的研究重点在于发展具有低电荷转移阻抗和宽温范围的新体系锂盐,低温电解液溶剂的研究重点在于发展具有高介电常数的EC溶剂与低熔点的PC溶剂混合体系,低温电解液添加剂的研究重点在于传统添加剂与新型添加剂的联用。 相似文献
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为研究飞行器和轨道空间站等低气压真空环境下,锂离子电池的循环安全性能。实验采用商用Li(NiCoMn)O2软包锂电池,在球舱近似真空压力下,进行0.5 C倍率循环充放电实验,并与常压环境下进行对比分析。研究发现:真空循环后,电池出现严重的大面积不可恢复形变和褶皱且厚度增加。随着循环次数增加,容量加速衰减,循环10次后容量低于80%。但恢复常压后,出现少部分容量的恢复;真空下扩大了充放电过程中的膨胀与收缩效应,加速了容量的衰减同时也造成部分容量的假性损失;电池周期性升温和降温速率加快,周期内温度不均匀性加剧,最大温差可达12.9℃,充放电的热稳定性和安全性变差,同时潜在的热灾害危害性变大。通过微分容量分析发现,低压真空环境下,所产生的活性锂的损耗和电极材料结构的损伤是降低电池循环充放性能的重要因素。 相似文献
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《Journal of power sources》2002,112(1):222-230
Laboratory-size LiNi0.8Co0.15Al0.05O2/graphite lithium-ion pouch cells were cycled over 100% DOD at room temperature and 60 °C in order to investigate high-temperature degradation mechanisms of this important technology. Capacity fade for the cell was correlated with that for the individual components, using electrochemical analysis of the electrodes and other diagnostic techniques. The high-temperature cell lost 65% of its initial capacity after 140 cycles at 60 °C compared to only a 4% loss for the cell cycled at room temperature. Cell ohmic impedance increased significantly with a elevated temperature cycling, resulting in some of loss of capacity at the C/2 rate. However, as determined with slow rate testing of the individual electrodes, the anode retained most of its original capacity, while the cathode lost 65%, even when cycled with a fresh source of lithium. Diagnostic evaluation of cell components including X-ray diffraction (XRD), Raman, CSAFM and suggest capacity loss occurs primarily due to a rise in the impedance of the cathode, especially at the end-of-charge. The impedance rise may be caused in part by a loss of the conductive carbon at the surface of the cathode and/or by an organic film on the surface of the cathode that becomes non-ionically conductive at low lithium content. 相似文献
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CHEN Jinpan ZHAO Hong ZHONG Guobin HU Qiaoming DENG Wen XU Lixin LAI Junke LI Chaofan CHEN Xiaochuan 《储能科学与技术》2019,8(3):602-608
锂离子电池是目前最具发展前景的高效二次电池和发展最快的化学储能电源,已成为各国竞相竞争的技术热点。专利技术能够反映某一技术领域创新发展的现状和历程,已成为开展竞争情报的重要信息源。本文从专利角度出发,通过对锂离子电池储能系统领域专利的分析,发现和了解锂离子储能系统的发展态势,以期为我国政府与企业的战略决策提供参考与借鉴。 相似文献
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为缩短锂电池生产工艺时间、节约成本,高温压力化成受到工艺人员的关注,本文以钴酸锂-石墨体系的软包装锂离子电池为研究对象,研究了高温压力化成工艺中温度对化成效果的影响。在某一压力作用下,采用不同化成温度,分析了不同化成温度对应的实际化成时间、化成电压、电压降以及电池倍率放电与高温处理的性能,结果显示化成温度越高,化成时间越长;在不同的温度下化成,对电池的循环性能及倍率性能影响不同。 相似文献
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针对软包锂离子电池放电过程中温度变化过程进行研究,依据电池产热基本理论,通过内阻实验及0.5 C放电倍率下的温升实验计算出瞬态生热率曲线,得出电池熵热系数,建立生热速率随放电深度不断变化的瞬态生热模型,基于该模型进行不同放电倍率的温度仿真模拟,并与实验进行对比。结果表明,温度变化模拟结果与实验相吻合,生热率变化模拟结果与实验计算值相符合,模型可以很好地模拟电池在不同放电倍率下的温度变化,对电池温升过程分析及电池热管理过程控制具有指导意义。 相似文献
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钛酸锂作为储能电池负极材料,在长循环和安全性上有突出的表现。通过对室温1C和2C倍率下循环的三元+钴酸锂/钛酸锂储能电池拆解,结合SEM、FTIR、XRD和EIS等分析手段,发现造成容量衰减和阻抗增大的原因出现在正极,由于正极与电解液发生反应,在表面生成界面膜,并且循环过程中界面膜不稳定,进一步消耗活性锂离子导致。另外,对这款电池的产气分析发现,所产生气体的主要成分为CO2和C2H6,原因可能是在制备电池过程中严格控制水分以及在电解液添加剂方面做了改进。 相似文献
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《International Journal of Hydrogen Energy》2020,45(4):2917-2924
High power density is essential for next-generation lithium-ion batteries. However, it is a great challenge to achieve high-power density and safety lithium-ion batteries due to the lack of reliable separators with uniform porosity, strong mechanical flexibility, and superior electrolyte uptake. Herein, a poly (vinylidene fluoride-co-hexafluoropropylene)/graphene oxide separator with uniform porosity, strong mechanical flexibility, and superior electrolyte uptake is prepared. The incorporation of graphene oxide into a poly (vinylidene fluoride-co-hexafluoropropylene) separator provides a large number of uniform diffusion channels for lithium ions to pass through by reducing the degree of crystallinity and increasing the pore uniformity of separator. In addition, the separator has superior mechanical property and thermal stability in comparison to commercial Celgard 2325 and pure poly (vinylidene fluoride-co-hexafluoropropylene) separators. This LiFePO4/Li cell with the prepared poly (vinylidene fluoride-co-hexafluoropropylene)/graphene oxide separator delivers a high capacity up to 160 mAh g−1 at 0.5C at room temperature and can be fully charged/discharged in 6 min (10C). 相似文献
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《Journal of power sources》2003,122(2):162-168
We have studied capacity fadings of acid-treated lithium manganese oxides in high-temperature storage. The amounts of dissolved lithium and manganese ions and consumed acids were determined in the reaction of lithium manganese oxides with acids. Discharge capacities of the acid-treated samples were measured and the small capacity fadings were observed. X-ray diffraction patterns of the acid-treated samples were almost the same as the one before the acid-treatment.After the acid-treated samples were stored in the EC/DMC solutions without Mn and Li ions at 80 °C for 24 h, they gave no further capacity fadings. On the other hand, after the storage under the same condition but in the EC/DMC solution containing both Mn and Li ions, the same acid-treated samples as above showed large capacity fadings. Thus, the following mechanism is deduced; the acid-treated lithium manganese oxide would react with Mn and Li ions in the solution, and its spinel structure would partly be fractured to result in the severe capacity fading. 相似文献
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Due to the various drawbacks of collecting temperature using embedded or patch thermocouple sensor, the internal temperature estimation is getting more and more attention in the field of lithium power battery. In this paper, the commercial 18650 LiFePO4 battery is selected to analyze the characteristic of Electrochemical Impedance Spectroscopy (EIS) from 0°C to 55°C of 0.1 to 10 000 Hz. The results reveal that there exists intrinsic relationship between the alternating current (AC) impedance phase shift and the internal temperature in the range of 10 to 100 Hz from 5 to 55°C. And the intrinsic relationship is not interfered with the State-of-Charge (SOC) and the State-of-Health (SOH). Subsequently, the relationship is described with a modified Arrhenius equation under the excitation frequency of 12, 44, and 79 Hz. Finally, a novel internal temperature estimation method is proposed by the AC impedance phase shift. The applicability and accuracy of the method are further verified via 10 temperature points. The results indicate that the estimation error is within 1°C in the common operating temperature range (15-45°C), suggesting that the proposed method can be applied to estimate battery internal temperature. Finally, the implementation system of real-time estimation for engineering application is constructed. 相似文献
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