新型结构自充电电池的研究

发布时间：2018-06-21 18:47

本文选题：自充电电池 + 纳米复合电极　；参考：《东北大学》2014年硕士论文

【摘要】：自充电电池是纳米发电机和锂离子电池有机结合的整体,可以使能量转换和能量存储融合到一步完成,提高能量转换和能量存储的总效率。目前自充电电池由于结构原因主要存在三个方面的问题：电场利用率低,机械能损耗较大,以及负极材料储锂性能低。本论文主要针对以上问题展开研究工作,提出解决方案。具体展开的研究工作内容如下：(1)使用纳米复合电极提高自充电电池性能。通过湿化学方法原位生长了CuO纳米阵列,再用旋涂的方法使PVDF包覆在CuO纳米阵列上制备出CuO/PVDF纳米复合电极,从而制备出集成自充电电池。由于CuO电极和PVDF隔膜之间更紧密的接触以及更大的接触面积,内部的压电电化学过程使得压电电场得到了更充分的利用,通过复合的压电电极集成自充电电池与非集成自充电电池相比,自充电效率得到有效提高。集成自充电电池在受到压力大小为18 N,频率为1.0 Hz时,经过240s的时间存储的容量为0.0247μAh,能量为6.12μJ,这是同等条件下非集成自充电电池(存储的容量和能量分别是0.0089 μAh和1.85μJ)的3倍。(2)使用柔性结构提高自充电电池性能。通过水热法制备的石墨烯纳米片作为电池的负极,商用LiCoO2作为电池的正极,PVDF薄膜作为压电隔膜,并用Kapton薄膜作为电池的电池壳取代原有的钢壳电池壳,最后用EVA进行封装,成功的制备出具有良好柔韧性的柔性自充电电池。柔性自充电电池的机械能利用率得到有效提高,自充电效率得到大幅度提升。柔性自充电电池大小为34N、频率为1.0 Hz的压力下,通过500 s的自充电过程,电压可以由500 mV上升到832mV,存储的电量为0.266μAh。而在相同条件下,钢壳结构的电池存储的电量仅为0.031μAh。柔性自充电电池可以收集转换并存储生活环境当中微小的机械能,在受到周期性弯曲时、经过利用手指点击以及通过车轮碾压,都可以成功的进行充电过程。柔性自充电电池由于其独特的柔性结构,不仅大幅度提高了自充电电池性能,还使自充电电池的应用范围更加广泛。(3)使用核壳结构准一维纳米材料提高负极材料储锂性能。通过该水热法制备了FeWO4纳米棒,并使用湿化学方法制备出FeWO4-SnO2核壳结构纳米棒。将FeWO4-SnO2核壳结构纳米棒作为电池的负极储锂具有较高的比容量,并且具有良好的循环稳定性能。核壳结构的FeWO4-SnO2纳米棒的可逆循环容量高达1286.9 mAh·g-1:远远地高出了单纯FeWO4纳米棒和Sn02的可逆容量。由于FeWO4与Sn02之间存在协同效应,FeWO4在嵌锂后会形成具有独特电化学性质的金属W和Fe纳米粒子,这可以使Sn02首次嵌锂过程中形成的不可逆Li20转变成可逆的L^从而大幅度提高了可逆容量。
[Abstract]:Self-rechargeable battery is an organic combination of nano-generator and lithium-ion battery. It can integrate energy conversion and energy storage into one step and improve the efficiency of energy conversion and energy storage. At present, there are three main problems in self-charging battery due to structural reasons: low utilization of electric field, large mechanical energy loss, and low lithium storage performance of negative electrode materials. This paper focuses on the above-mentioned research work and proposes solutions. The main contents of the research are as follows: (1) Nano-composite electrode is used to improve the performance of self-charging battery. CuO nanoarrays were grown in situ by wet chemical method. Then PVDF was coated on CuO nanoarrays by spin coating method to prepare CuO / PVDF nanocomposite electrodes, thus the integrated self-rechargeable batteries were prepared. Because of the closer contact and larger contact area between CuO electrode and PVDF diaphragm, the piezoelectric electric field is utilized more fully because of the internal piezoelectric electrochemical process. Compared with non-integrated self-rechargeable battery, the self-charging efficiency of composite piezoelectric electrode integrated self-charging battery is improved effectively. The integrated self-charging battery is subjected to a pressure of 18 N and a frequency of 1.0 Hz. The time storage capacity of 240s is 0.0247 渭 Ahand the energy is 6.12 渭 J. this is three times of the non-integrated self-rechargeable battery (storage capacity and energy are 0.0089 渭 Ah and 1.85 渭 J respectively) under the same conditions. The flexible structure is used to improve the performance of the self-rechargeable battery. Graphene nanocrystals prepared by hydrothermal method were used as negative electrode, commercial LiCoO2 as positive electrode PVDF film as piezoelectric diaphragm, Kapton film as battery shell instead of steel shell, and EVA as encapsulation. A flexible self-rechargeable battery with good flexibility was successfully prepared. The mechanical energy utilization of flexible self-rechargeable battery is improved effectively and the self-charging efficiency is greatly improved. The voltage of the flexible self-rechargeable battery can be increased from 500mV to 832mV under the pressure of 34N and the frequency of 1.0Hz, and the stored energy is 0.266 渭 Ah.Through the self-charging process of 500s, the voltage can be increased from 500mV to 832mV. Under the same conditions, the battery storage capacity of the steel shell structure is only 0.031 渭 Ah. Flexible self-rechargeable batteries can collect and store the tiny mechanical energy in the living environment. When they are subjected to periodic bending, they can be successfully charged through finger clicks and wheel compaction. Because of its unique flexible structure, flexible self-rechargeable battery not only greatly improves the self-charging battery performance, but also makes the self-rechargeable battery more widely used. (3) the core shell structure quasi-one-dimensional nano-materials are used to improve the lithium storage performance of negative electrode materials. Fewo _ 4 nanorods were prepared by hydrothermal method, and Fewo _ 4-SnO _ 2 nanorods with core-shell structure were prepared by wet chemical method. Fewo _ 4-SnO _ 2 nanorods have high specific capacity and good cycling stability. The reversible cycle capacity of core-shell Fewo _ 4-SnO _ 2 nanorods is up to 1286.9 mAh g-1, which is far higher than that of pure FeWO4 nanorods and Sn02 nanorods. Because of the synergistic effect between FeWO4 and Sn02, FeWO _ 4 can form metal W and Fe nanoparticles with unique electrochemical properties after lithium intercalation. This can make the irreversible Li20 formed in the first lithium intercalation process of Sn02 into a reversible L ^, thus greatly increasing the reversible capacity.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM910

【相似文献】