Very High Surface Capacity Observed Using Si Negative Electrodes Embedded in Copper Foam as 3D Current Collectors
Very High Surface Capacity Observed Using Si Negative Electrodes Embedded in Copper Foam as 3D Current Collectors
复制标题
DOI：
10.1002/aenm.201301718
复制
发表时间：
2014-06-01
影响因子：
27.8
通讯作者：
Lestriez, Bernard
中科院分区：
文献类型：
--
作者：
Mazouzi, Driss;Reyter, David;Lestriez, Bernard
铜泡沫被评估为金属箔集流体的替代品，以创建3D复合电极，目的是生产具有高负载的Si基阳极。通过将浆料浇铸到泡沫的孔隙中来制备电极。通过这种设计，负载量和表面容量可以达到高达10 mg cm（-2）和10 mAh cm（-2）的值。与常见的2D设计相比，3D铜框架在循环寿命（在具有商业微米颗粒的10 mg cm（-2）的Si负载下超过400次循环）和功率性能方面显示出很大的优势。泡沫壁上的复合涂层的薄度有利于在循环和快速锂离子扩散时更好地保护电子布线。通过使用碳纳米纤维（CNF）而不是炭黑（CB），在具有锂金属作为对电极的半电池中实现了更高的库仑效率。在实践中，与传统设计的石墨/LiFePO 4叠层相比，对于Cu泡沫-硅//LiFePO 4叠层，达到更高表面容量的可能性可以允许体积和重量能量密度分别显著增加23%和19%。
Cu foam is evaluated as a replacement for metal foil current collectors to create 3D composite electrodes with the objective to produce Si-based anodes with high loadings. The electrodes are prepared by casting the slurry into the porosity of the foam. With such a design, the loading and the surface capacity can reach values as high as 10 mg cm(-2) and 10 mAh cm(-2). Compared to the common 2D design, the 3D copper framework shows a great advantage in the cycle life (more than 400 cycles at a Si loading of 10 mg cm(-2) with commercial micrometric particles) and power performance. The thinness of the composite coating on the foam walls favors a better preservation of the electronic wiring upon cycling and fast lithium ion diffusion. A higher coulombic efficiency in half cells with lithium metal as the counter electrode is achieved by using carbon nanofibers (CNF) rather than carbon black (CB). The possibility to reach, in practice, higher surface capacity could allow a significant increase in both the volumetric and gravimetric energy densities by 23% and 19%, respectively, for the Cu foam-silicon//LiFePO4 stack compared to the graphite/LiFePO4 stack of traditional design.