Koo Ji-Hye, Paek Seung-Min
Department of Chemistry, Kyungpook National University, Daegu 41566, Korea.
Nanomaterials (Basel). 2021 Jan 27;11(2):319. doi: 10.3390/nano11020319.
Germanium/germanium oxide nanoparticles with theoretically high discharge capacities of 1624 and 2152 mAh/g have attracted significant research interest for their potential application as anode materials in Li-ion batteries. However, these materials exhibit poor long-term performance due to the large volume change of 370% during charge/discharge cycles. In the present study, to overcome this shortcoming, a Ge/GeO/graphene composite material was synthesized. Ge/GeO nanoparticles were trapped between matrices of graphene nanosheets to offset the volume expansion effect. Transmission electron microscopy images revealed that the Ge/GeO nanoparticles were distributed on the graphene nanosheets. Discharge/charge experiments were performed to evaluate the Li storage properties of the samples. The discharge capacity of the bare Ge/GeO nanoparticles in the first discharge cycle was considerably large; however, the value decreased rapidly with successive cycles. Conversely, the present Ge/GeO/graphene composite exhibited superior cycling stability.
理论放电容量分别为1624和2152 mAh/g的锗/氧化锗纳米颗粒，因其作为锂离子电池负极材料的潜在应用而引起了广泛的研究兴趣。然而，由于在充放电循环过程中370%的巨大体积变化，这些材料的长期性能较差。在本研究中，为克服这一缺点，合成了一种Ge/GeO/石墨烯复合材料。Ge/GeO纳米颗粒被困在石墨烯纳米片的基体之间，以抵消体积膨胀效应。透射电子显微镜图像显示，Ge/GeO纳米颗粒分布在石墨烯纳米片上。进行充放电实验以评估样品的锂存储性能。裸露的Ge/GeO纳米颗粒在第一个放电循环中的放电容量相当大；然而，该值随着连续循环迅速下降。相反，目前的Ge/GeO/石墨烯复合材料表现出优异的循环稳定性。
