Song Huiyu, Chen Xilong, Zheng Guangli, Yu Xijuan, Jiang Shangfeng, Cui Zhiming, Du Li, Liao Shijun
The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering , South China University of Technology , Guangzhou 510641 , China.
Key Laboratory of Opticelectric Sensing and Analytical Chemistry for Life Science, MOE, College of Chemistry and Molecular Engineering , Qingdao University of Science and Technology , Qingdao 266042 , China.
ACS Appl Mater Interfaces. 2019 May 22;11(20):18361-18367. doi: 10.1021/acsami.9b01694. Epub 2019 May 8.
Using lithium metal as anode in lithium batteries has attracted great attention due to its ultrahigh theoretical capacity of 3860 mA h g. However, the uneven deposition of lithium will cause dendrites, resulting in a poor cycling performance. Herein, a dendrite-free Li composite anode is developed by anchoring Ag nanoparticles in a wood-derived carbon (WDC) frame. The composite anode is integrally formed and has enough room for Li deposition due to the aligned open channels preserved from natural wood, which can decrease anode volume change greatly during cycling. The Ag nanoparticles, serving as seeds of lithium deposition, can help in the even deposition of lithium in the channels of carbon matrix due to their lithiophilicity and then avoid lithium dendrite formation. The composite anode exhibits excellent cyclic performance over 450 h at 1 mA cm and over 300 h at 3 mA cm. The full cell of Ag-WDC@LFP also exhibits the smallest electrochemical polarization from 0.2 to 5 C, and a stable specific capacity and a high Coulombic efficiency at 1 C after a long time cycle. These results indicate that Ag nanoparticles play an important role in restraining dendrite formation during lithium plating/stripping. The wood-derived composite cathode can achieve no lithium dendrite formation and can be applied in other storage batteries.
在锂电池中使用锂金属作为阳极因其3860 mA h g的超高理论容量而备受关注。然而,锂的不均匀沉积会导致枝晶形成,从而导致循环性能不佳。在此,通过将银纳米颗粒锚定在木材衍生碳(WDC)框架中开发了一种无枝晶锂复合阳极。该复合阳极整体成型,由于天然木材保留的排列开放通道而具有足够的锂沉积空间,这可以在循环过程中大大降低阳极体积变化。银纳米颗粒作为锂沉积的种子,由于其亲锂性,有助于锂在碳基体通道中均匀沉积,从而避免锂枝晶形成。该复合阳极在1 mA cm下表现出超过450 h的优异循环性能,在3 mA cm下表现出超过300 h的优异循环性能。Ag-WDC@LFP全电池在0.2至5 C范围内也表现出最小的电化学极化,并且在长时间循环后在1 C下具有稳定的比容量和高库仑效率。这些结果表明,银纳米颗粒在抑制锂电镀/剥离过程中的枝晶形成方面起着重要作用。木材衍生的复合阴极可以实现无锂枝晶形成,并可应用于其他蓄电池。