Native Void Space for Maximum Volumetric Capacity in Silicon-Based Anodes

Journal Article · Wed Dec 11 04:00:00 EST 2019 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.9b03583· OSTI ID:1615020

Yeom, Su Jeong ^[1]; Lee, Cheolmin ^[2]; Kang, Sujin ^[2]; Wi, Tae-Ung ^[2]; Lee, Chanhee ^[2]; Chae, Sujong ^[3]; Cho, Jaephil ^[4]; Shin, Dong Ok ^[5]; Ryu, Jungki ^[2]; Lee, Hyun-Wook ^[2]

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1. Ulsan National Insitute of Science and Technology
2. Ulsan National Institute of Science and Technology
3. BATTELLE (PACIFIC NW LAB)
4. Ulsan National Institute of Science and Technolog
5. Electronics and Telecommunication Research Institute

Volumetric energy density is considered a primary factor in developing high-energy batteries. Despite its significance, less efforts have been devoted to its improvement. Silicon-based materials have emerged as next-generation anodes for lithium-ion batteries due to their high specific capacity. However, their volumetric capacities are limited by the volume expansion rate of silicon, which restricts mass loading in the electrodes. To address this challenge, we introduce porous silicon templated from earth-abundant minerals with native internal voids, capable of alleviating volumetric expansion during repeated cycles. In situ transmission electron microscopy analysis allows the precise determination of the expansion rate of silicon, thus presenting an analytical model for finding the optimal content in silicon/graphite composites. The inner pores in silicon reduce problems associated with its expansion and allow higher silicon loading of 42% beyond the conventional limitations of 13–14%. Consequently, the anode designed in this work can deliver a volumetric capacity of 978 mAh cc–1. Thus, suppressing volume expansion with natural abundant template-assisted materials opens new avenues for cost-effective fabrication of high volumetric capacity batteries.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1615020
• Report Number(s): PNNL-SA-149333
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 12 Vol. 19
• Country of Publication: United States
• Language: English