共查询到20条相似文献,搜索用时 78 毫秒
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LiFePO4因具有高的比容量、良好的循环性、环境友好等特点,成为目前最受关注的锂离子电池正极材料。概述了LiFePO4的结构和电化学性能,介绍了LiFePO4主要的几种制备方法,包括固相法、水热法、微波法。同时阐述了提高LiFePO4电化学性能所做的改性研究,并对该材料的发展方向进行了展望。 相似文献
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富锂锰正极材料(Li-rich manganese cathode material,LMCM)因高比容量(>250 mAh·g-1)、低成本等优势,被视为最具前景的下一代锂离子电池正极材料。然而,该正极材料在循环过程中存在不可逆的结构转变等问题,造成首次不可逆容量损失高、倍率性能差、能量衰减和电压衰减等问题。通过体掺杂、表面包覆和结构优化设计等策略可一定程度上改善LMCM存在的以上问题。本文重点介绍LMCM存在的问题及改性研究工作,分析LMCM存在的问题及起因,详细阐述目前主要改性方法的研究现状,并讨论各种改性方法的优缺点及今后的重点研究方向。此外,本文还分析目前LMCM材料产业化进展和面临的主要挑战。由于自身存在的问题和配套材料发展缓慢,目前仅在部分企业实现小批量生产。 相似文献
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Herein, a comprehensive investigation of the effect of calcination temperature on the physicochemical properties of full-concentration-gradient Li[Ni0.78Co0.10Mn0.12]O2 (FCG NCM78) and the electrochemical performance of FCG NCM78 cathodes was conducted. The electrochemical performance of the FCG NCM78 cathode was significantly influenced by the physical properties of FCG NCM78, such as crystallinity, compositional gradient, and morphology. The crystallinity of FCG NCM78 increased with increasing calcination temperature; however, the compositional gradient and radial alignment of rod-shaped primary particles increasingly disappeared at calcination temperatures exceeding the optimal calcination temperature. FCG NCM78 calcined at the optimal calcination temperature retained the morphological texture of its precursor and demonstrated high crystallinity; the resulting cathode exhibited remarkable cycling stability, thereby retaining 86.3% of its initial capacity after 4000 cycles, and superior rate capability due to the availability of nearly straight diffusion paths for Li-ion transport across adjacent primary particles. In contrast, excessively coarsened FCG NCM78 cathode particles, which are obtained at high calcination temperatures, develop permanent microcracks during cycling, thereby facilitating severe structural damage of the cathode material by parasitic surface reactions and the rapid deterioration of the solid electrolyte interphase layer on the graphite anode surface due to the crossover of dissolved transition-metal ions. Therefore, for superior electrochemical performance, the physicochemical properties of FCG cathode materials should be carefully optimized by controlling the calcination process. 相似文献
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锂离子电池正极材料磷酸铁锂:进展与挑战 总被引:2,自引:1,他引:2
磷酸铁锂(LiFePO4)由于安全性能好、循环寿命长、原材料来源广泛、无环境污染等优点被公认为是最具发展潜力的锂离子动力与储能电池正极材料。经过10余年的深入研究,LiFePO4已经进入实用化阶段,综述了磷酸铁锂材料近年来在基础和应用研究方面的最新进展。 相似文献
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锂离子电池正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的制备与表征 总被引:1,自引:0,他引:1
以乙酸锂、硝酸镍、硝酸钴和乙酸锰为原料,通过高温固相法,分别采用一次烧结和二次烧结合成了LiNi1/3Co1/3Mn1/3O2。采用X射线衍射、扫描电镜分析以及电化学测试等手段对LiNi1/3Co1/3Mn1/3O2的微观结构、表面形貌和电化学性能进行了研究。结果表明,高温固相法能得到结晶良好的LiNi1/3Co1/3Mn1/3O2,但二次烧结提高了材料的I(003)/I(104)值,降低了c/a值,得到的LiNi1/3Co1/3Mn1/3O2具有更完善的层状结构和更优良的电化学性能。 相似文献
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低成本、高能量密度、高安全性的镁电池有望应用在未来大规模储能和动力汽车等领域。然而,镁电池目前仍处于初步发展的阶段,正极是限制电池性能的关键原因。由于Mg2+电荷密度高,在正极材料中扩散缓慢,因此如何提高正极材料的电化学性能是镁电池研究的重点与难点。本文通过分析正极材料的相关研究,总结出提升正极材料电化学性能的6种策略,分别为减小粒径、借助溶剂的屏蔽效应、增大层间距、调控阴离子、开发新结构和发展双离子电池。通过明确策略有效的根本原因、分析策略的优势与局限性,为高性能镁电池正极材料的开发提供有价值的指导。最后,对镁电池正极的发展现状进行总结,并对镁电池的正极及整个电池体系的未来发展趋势进行展望。 相似文献
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Core@shell and concentration-gradient particles have attracted much attention as improved cathodes for Li-ion batteries (LIBs). However, most of their preparation routes have employed a precisely-controlled co-precipitation method. Here, we report a facile preparation route of core@shell and concentration-gradient spinel particles by dry powder processing. The core@shell particles composed of the MnO2 core and the Li(Ni,Mn)2O4 spinel shell are prepared by mechanical treatment using an attrition-type mill, whereas the concentration-gradient spinel particles with an average composition of LiNi0.32Mn1.68O4 are produced by calcination of their core@shell particles as a precursor. The concentration-gradient LiNi0.32Mn1.68O4 spinel cathode exhibits the high discharge capacity of 135.3 mA h g−1, the wide-range plateau at a high voltage of 4.7 V and the cyclability with a capacity retention of 99.4% after 20 cycles. Thus, the facile preparation route of the core@shell and concentration-gradient particles may provide a new opportunity for the discovery and investigation of functional materials as well as for the cathode materials for LIBs. 相似文献
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AbstractCore@shell and concentration-gradient particles have attracted much attention as improved cathodes for Li-ion batteries (LIBs). However, most of their preparation routes have employed a precisely-controlled co-precipitation method. Here, we report a facile preparation route of core@shell and concentration-gradient spinel particles by dry powder processing. The core@shell particles composed of the MnO2 core and the Li(Ni,Mn)2O4 spinel shell are prepared by mechanical treatment using an attrition-type mill, whereas the concentration-gradient spinel particles with an average composition of LiNi0.32Mn1.68O4 are produced by calcination of their core@shell particles as a precursor. The concentration-gradient LiNi0.32Mn1.68O4 spinel cathode exhibits the high discharge capacity of 135.3 mA h g?1, the wide-range plateau at a high voltage of 4.7 V and the cyclability with a capacity retention of 99.4% after 20 cycles. Thus, the facile preparation route of the core@shell and concentration-gradient particles may provide a new opportunity for the discovery and investigation of functional materials as well as for the cathode materials for LIBs. 相似文献