Highly Conductive, Lightweight, Low-Tortuosity Carbon Frameworks as Ultrathick 3D Current Collectors

5 years ago

Highly Conductive, Lightweight, Low-Tortuosity Carbon Frameworks as Ultrathick 3D Current Collectors

Jianwei Song, Yiju Li, Ying Zhang, Jia Xie, Liangbing Hu, Yanbin Wang, Wei Luo, Yudi Kuang, Chaoji Chen, Glenn Pastel, Yonggang Yao

The growing demand for advanced energy storage techniques and devices has driven the energy storage market to strive for higher performance, longer cycling life, and better safety. Thick electrode design enabling more electroactive materials has the potential to significantly improve the energy density on device level yet faces major challenges of slow ion transport and high deformability. Here, inspired by natural wood materials with aligned channels along the tree growth direction, a highly conductive, lightweight, and low-tortuosity carbon framework (CF) directly carbonized from natural wood as an ultrathick 3D current collector is demonstrated. Benefiting from the uniqueness of the multichanneled CF, an ultrathick 3D electrode of lithium iron phosphate filled carbon framework with a large thickness of 800 µm and active material mass loading of 60 mg cm−2 delivers a rational capacity of 7.6 mAh cm−2 (95 Ah L−1 based on volume), long cycling life, and lower deformability with enhanced mechanical properties. This work presents a design concept for thick electrode toward high performance energy storage devices that are not limited to lithium-ion batteries. A nature-inspired low-tortuosity 3D current collector is developed by directly carbonizing wood material with nature-made aligned channels. Electrode materials, lithium iron phosphate as an example, can be facilely infiltrated into the channels of the 3D current collector, forming an ultrathick 3D electrode with low tortuosity, large thickness, high mass loading, high energy density, and low deformability.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/aenm.201700595