Researchers from China recently developed a strategy to reuse waste graphite anodes of spent lithium-ion batteries. They transformed the recovered graphite into a new cathode material for dual-ion batteries through a two-step treatment.
The recycled graphite shows improved resistance to degradation and enhanced cycling performance. This simple approach further adds more sustainability to lithium-ion-based energy solutions. This study is available in the journalE欧洲杯线上买球science。
Study:Advanced cathode for dual-ion batteries: Waste-to-wealth reuse of spent graphite from lithium-ion batteries。图片来源：lightboxx/shutterstock.com
Reuse of Graphite from Anode Material: A Sustainable Approach
随着对锂离子电池（LIB）的需求增加和电极材料的稀缺性，能源部门正在推动更可持续的方法。欧洲杯足球竞彩由于能量密度高，循环寿命和出色的便携性，LIB将在未来几年中仍然是高度要求的选择。
Currently, the commercial cathode materials in LiBs consist of various oxides or phosphates of lithium (Li), cobalt (Co), nickel (Ni), manganese (Mn), and iron (Fe), whereas common anode materials are carbon-based. The reuse of the spent carbon materials in cathodes can resolve the economic, environmental, and ethical dilemma.
The most common carbon materials in the anodes of LiBs are graphite, soft carbon, hard carbon, carbon nanotubes.
（一种）RNG合成过程的示意图；（b）XRD patterns;（C）NMG，PNG和RNG的拉曼光谱。图片来源：Yang，J等人，Escience欧洲杯线上买球
Graphite dominates the LIB anode market because of its special layered structure that facilitates relatively stable insertion and extraction of Li+离子。此外，它具有良好的稳定性，高电导率（〜0.4 eV带隙），较低的锂插入电位（0.01-0.2 V）和较高的理论能力（372 mAh g–1）than other carbon materials.
传统上，高温应压是从阳极恢复石墨的主要方法。在高温铝中，石墨与阴极一起焚化，阴极效率低，并释放出大量的温室气体。
双离子电池和石墨之间的协同作用
双离子电池（DIB），由于高输出电压和高能量密度的优势，引起了很多关注。在DIB中，阳离子和阴离子同时参与电池的电化学反应。阴离子像碱金属离子一样经历互插反应。
同时，已经广泛研究了碳材料作为允许各种阳离子和阴离欧洲杯足球竞彩子插入的电极材料。其中，石墨材料作为DIB的阴极材料的发展最欧洲杯足球竞彩多。因此，低成本的碳材料和用于DIBS中阴极的碱性金属电池的组合是有效且可持续的。欧洲杯足球竞彩
（一种）GCD curves at 200 mA g-1;（b）简历曲线；（C）rate performance and（d）NMG，PNG和RNG的循环性能。图片来源：Yang，J等人，Escience欧洲杯线上买球
关于研究
研究人员从LIBS的阳极采购了回收的负石墨（RNG），并通过轻松的两步过程将其转化为DIB的阴极。
To obtain RNG, primitive negative graphite (PNG) powder recovered from the negative electrodes of waste LIBs is mixed with pure ethanol, and the obtained samples are heated at 1300 ℃ for 2.5 hours in an argon atmosphere. Finally, several experiments were carried out to measure the performance of the prepared sample and compared with that of PNG and natural modified graphite (NMG).
观察
从X射线衍射（XRD）来看，很明显，RNG的（002）峰与NMG相比向右移动，而PNG的峰向左移动，表明RNG的层间距会降低，而PNG的层降低，而PNG的层则增加了。。
热处理后，石墨层间距会减小，而石墨中的填料密度和秩序程度则增加。同样，它表明RNG的石墨化程度为87.74％，高于PNG和NMG的石墨化程度。
这种恢复方法恢复了寿命末期石墨的形态和晶体结构。长循环后，石墨的扭曲层结构通过适当的层间距恢复，用于通过热解碳的涂层进行阴离子插入。此外，固体电解质相（SEI）组件的热解形成了无定形碳层，可防止电极降解并增强其循环性能。
HRTEM图像（一种）初始rng和（b）70个周期后的RNG。（C）XRD patterns of initial RNG and RNG after 70 cycles.（d）提出的与RNG中PF6-插入的GIC的机制。图片来源：Yang，J等人，Escience欧洲杯线上买球
What is the Performance of the RNG?
The researchers developed a facile recycling method through a simple two-step process. The end-of-life anode graphite from LIBs is directly converted to RNG for use as a cathode in DIBs. The recycling method reinstates the crystal structure and morphology of RNG and restores its regular layer structure with preferable layer spacing. The RNG demonstrates a high reversible capacity of 87 mAh g–1在200 ma g–1, which was equivalent to that of commercial new graphite.
RNG可以成功地用于li-dibs，na-dibs和k-dibs。这种便捷的回收方法将寿命末端的阳极石墨变成了具有有希望的潜力和出色的电化学性能以及可持续能量方法的阴极材料。
参考
Yang，J.，Zhao，X.，Li，W.，Liang，H.，Gu，Z.，Liu，Y.从锂离子电池的托运石墨重复使用，E欧洲杯线上买球science，2021年，ISSN 2667-1417，https://www.欧洲杯线上买球sciendirect.com/science/article/pii/s2667141721000227?via%3dihub
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