Zhang Chunmei, Jiao Yalong, He Tianwei, Ma Fengxian, Kou Liangzhi, Liao Ting, Bottle Steven, Du Aijun
School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4001, Australia.
Phys Chem Chem Phys. 2017 Oct 4;19(38):25886-25890. doi: 10.1039/c7cp04758d.
Two-dimensional (2D) materials are promising for use in lithium (Li) electrodes due to their high surface ratio. By using density functional theory (DFT) calculations, we investigate the adsorption and diffusion of Li on a newly predicted 2D GeP material [Nano Lett., 2016, 17, 1833]. The most favourable adsorption sites for Li are identified, and a semiconducting to metallic transition induced by Li adsorption is found, which indicates excellent electrical conductivity. The GeP monolayer has an estimated capacity of 648 mA h g, which is almost twice that of commercially used graphite (375 mA h g). During full Li intercalation, the GeP layer undergoes only 1.2% lattice parameter reduction. Moreover, GeP possesses the advantages of a small diffusion barrier (∼0.5 eV) and low average open-circuit voltages (∼0.4 V). Our results highlight a new class of promising anode materials, i.e. 2D phosphide, as potential rechargeable lithium batteries with ultrahigh-capacity, superior ionic conductivity, and low average open-circuit voltage.
二维（2D）材料因其高比表面积而有望用于锂（Li）电极。通过使用密度泛函理论（DFT）计算，我们研究了Li在一种新预测的二维GeP材料上的吸附和扩散[《纳米快报》，2016年，17卷，1833页]。确定了Li最有利的吸附位点，并发现Li吸附诱导了从半导体到金属的转变，这表明其具有优异的导电性。GeP单层的估计容量为648 mA h/g，几乎是商业使用的石墨（375 mA h/g）的两倍。在完全锂嵌入过程中，GeP层的晶格参数仅降低1.2%。此外，GeP具有扩散势垒小（约0.5 eV）和平均开路电压低（约0.4 V）的优点。我们的结果突出了一类新的有前景的负极材料，即二维磷化物，作为具有超高容量、优异离子导电性和低平均开路电压的潜在可充电锂电池。
