Abstract Germanene with high volume/surface ratio similar to graphene is expected to be promising electrodes for supercapacitors. Based on first-principles method, the stability, quantum capacitance, and surface charge storage of vacancy-defected, doped and co-doped germanene were studied. The results suggested that the enhancement of quantum capacitance (CQ) by introducing of transition-metal dopants (Ti, Cr, Mn, and Co) were more effective than that of B/N/Al-dopants. Furthermore, the co-doped germanene exhibited higher quantum capacitance than single-doped, which also owned very high CQ at negative local potential and was potential used as cathode materials for supercapacitors. The presence of vacancy-defect improved the CQ of germanene, whereas the co-doped defected germanene can’t exhibit any advantages than co-doped prefect germanene. In other words, the co-doping is more effective than vacancy-defect to enhance the quantum capacitance of germanene.

中文翻译：

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受空位和共掺杂影响的基于锗烯的超级电容器电极的量子电容：第一性原理研究

摘要 具有类似于石墨烯的高体积/表面比的锗烯有望成为超级电容器的有前途的电极。基于第一性原理方法，研究了空位缺陷、掺杂和共掺杂锗烯的稳定性、量子电容和表面电荷存储。结果表明，通过引入过渡金属掺杂剂（Ti、Cr、Mn 和 Co）来增强量子电容（CQ）比 B/N/Al 掺杂剂更有效。此外，共掺杂锗烯比单掺杂锗烯表现出更高的量子电容，在负局部电位下也具有非常高的 CQ，可用作超级电容器的阴极材料。空位缺陷的存在提高了锗烯的CQ，而共掺杂的缺陷锗烯与共掺杂的完美锗烯相比没有任何优势。