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锂离子电池用层状LiMnO2基正极材料的研究进展 总被引:4,自引:0,他引:4
层状LiMnO2材料因其结构不稳定、循环性能差,因而需对其进行掺杂改性.层状锰系衍生物具有比容量高、循环性能稳定等优点,已成为锂离子电池新的发展方向.介绍了目前对LiMnO2的掺杂改性研究,对多元层状锰基固溶体正极材料作了重点阐述.总结了近年来关于多元层状锰基正极材料的研究发展,介绍了其晶体结构、电化学性能、合成与制备技术,以及进一步的改性研究.如果多元层状固溶体材料的高倍率放电性能得到进一步的提高,则其必将成为新的一代锂离子电池正极的首选材料. 相似文献
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模板法制备层状锰酸锂正极材料及其电化学性能研究 总被引:1,自引:0,他引:1
以商业级大孔径硅胶为模板,利用硅胶的多孔结构制备了具有纳米尺寸的层状锰酸锂正极材料(o-LiMnO_2),采用XRD、SEM和N_2吸附技术对样品进行表征,结果表明模板法制备的LiMnO_2结晶度较好,纯度较高,颗粒尺寸大约30 nm左右.用循环充放电测试考察了产物的电化学性能,结果显示了模板法制备的层状锰酸锂具有较好的电化学循环性能,30次充放电后仍能保持较高容量,而未采用模扳法制备的微米级材料容量衰减严重. 相似文献
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镍钴锰酸锂三元材料的化学组成最初出现在20世纪90年代末期的钴酸锂和镍酸锂的掺杂研究中,其作为独立体系材料的研发开始于2001年。在该化合物中,镍呈现正二价,是主要的电化学活性元素;锰呈现正四价,不参与电化学反应,只对材料的结构稳定性和热稳定性提供保证;钴是正三价,部分参与电化学反应,其主要作用是保证材料层状结构的规整度、降低材料电化学极化、提高其倍率性能。该材料具有比容量高、高电压下结构稳定、安全性较好等优点,是目前看来最有应用前景的一种锂离子电池正极材料。 相似文献
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北京市重大科技项目“锂离子电池正极材料锰酸锂的产业化技术开发”最近通过了北京市科委组织的专家验收。该项目由中信国安盟固利电源技术有限公司实施,独立开发出整套规模化生产装置,率先建成年产200吨电化学性能优越的锰酸锂生产线。 相似文献
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Nitrogen‐containing polymeric carbon as anode materials for the lithium ion secondary battery is prepared from polyacrylonitrile (PAN) and melamine–formaldehyde resin (MF) at 600 and 800°C. Its physicochemical properties were investigated through elemental analysis, X‐ray powder diffraction, X‐ray photoelectron spectroscopy, and measurement of specific surface area. Results show that this kind of carbon is amorphous. Nitrogen atoms exist in the prepared polymeric carbon mainly as two states, that is, graphene nitrogen and conjugated nitrogen, and favor the enhancement of reversible lithium capacity. All the prepared polymeric carbon has a reversible capacity higher than that of the theoretic value of graphite, 372 mAh/g, and the highest reversible capacity can be up to 536 mAh/g. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1735–1741, 2000 相似文献
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Carbon nanobeads (CNBs) were prepared by reacting cyclohexachlorobenzene with dispersed sodium metal at 200 °C for 4 h. The CNBs prepared in this manner formed uniform nanobeads, with sizes ranging from 100 to 300 nm. Heating resulted in a reduction in the size of the CNBs, and improvements in their degree of crystallinity. The nanosized carbon materials considerably increased the surface area of the powder, reducing the distance of the intercalation/deintercalation pathway, substantially improving the charge capacity of the lithium ion battery at a high charging rate. The charge capacity of CNBs was found to be 238 mAh g−1, while that of commercial MCMB reached only 36 mAh g−1, when the charging rate was 1C (372 mAh g−1). As the charging rate was further increased to 2C (744 mAh g−1) and 3C (1116 mAh g−1), the charge capacities of CNBs dropped to 173 and 111 mAh g−1, respectively. The cyclic performance of the CNBs was measured and found to be significantly improved in comparison to other carbonaceous materials, for up to 100 cycles. Although cyclic performance did result in a gradual reduction in capacity, the CNBs still greatly exceeded the capacity of MCMB. These results clearly demonstrate the potential role of CNBs as anodes for high capacity Li ion batteries for use in the automobile industry. 相似文献
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新能源汽车的高速发展,对电池材料的能量密度提出了更高的要求。SnO2-C复合材料因比容量高、倍率性能好、资源丰富、价格低廉等优点而被视为下一代锂、钠离子电池最有潜力的负极材料之一。基于SnO2-C复合材料的尺寸变化和尺寸复合方式,本文对SnO2-C复合材料进行了分类,并且详细综述了SnO2-C复合材料的最新代表性进展,重点涉及尺寸设计公式以及由此产生的协同效应和提高性能的潜力。最后,讨论了该领域未来的发展方向和前景,鉴于协同效应的优良体现,以后该研究将偏于多重复合方向,同时会探索出简单、环保、廉价的合成工艺,不断向商品化的方向靠近。其概念和策略对实际锂离子、钠离子电池金属氧化物-C复合材料的合理设计和可扩展构造提供了一些依据。 相似文献
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