Enabling Ultrathick Electrodes via a Microcasting Process for High Energy and Power Density Lithium‐Ion Batteries
Enabling Ultrathick Electrodes via a Microcasting Process for High Energy and Power Density Lithium‐Ion Batteries
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DOI：
10.1002/aenm.202201353
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发表时间：
2022-07
影响因子：
27.8
通讯作者：
T. Plateau;Hiep Pham;Yaqi Zhu;M. Leu;Jonghyun Park
中科院分区：
文献类型：
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作者：
T. Plateau;Hiep Pham;Yaqi Zhu;M. Leu;Jonghyun Park
加厚电极是增加高能量和低成本锂离子电池活性材料含量的一种有效方法，但电荷传输的限制和巨大的机械应力的产生导致性能差和最终的电池故障。本文报道了一种新的电极制造工艺，称为微铸造，使超厚电极，解决了比容量和面积/体积容量之间的权衡。所提出的μ铸造基于图案化的刀片，使得能够容易地制造3D电极结构。该研究揭示了µ铸造超厚电极的控制特性，以及如何同时提高电池的能量/功率性能。该工艺有助于形成短扩散路径结构，从而最大限度地减少嵌入引起的应力，提高能量密度和电池稳定性。这项工作还调查了结构完整性，孔隙率和糊状流变学的问题，并分析了由于外力的机械性能。与传统的厚电极相比，这种微铸造工艺可以实现更有效地利用NMC-811（LiNi0.8Mn0.1Co0.1O2）阴极和中间相碳微珠阳极活性材料的超厚电极（280 μ m），允许高质量负载（35.7 mg cm − 2），200次循环后的比容量高40%，面容量高30%，高C倍率性能和更长的循环寿命。
Thickening electrodes is one effective approach to increase active material content for higher energy and low‐cost lithium‐ion batteries, but limits in charge transport and huge mechanical stress generation result in poor performance and eventual cell failure. This paper reports a new electrode fabrication process, referred to as µ‐casting, enabling ultrathick electrodes that address the trade‐off between specific capacity and areal/volumetric capacity. The proposed µ‐casting is based on a patterned blade, enabling facile fabrication of 3D electrode structures. The study reveals the governing properties of µ‐casted ultrathick electrodes and how this simultaneously improves battery energy/power performance. The process facilitates a short diffusion path structure that minimizes intercalation‐induced stress, improving energy density and cell stability. This work also investigates the issues with structural integrity, porosity, and paste rheology, and also analyzes mechanical properties due to external force. The µ‐casting enables an ultrathick electrode (≈280 µm) that more effectively utilizes NMC‐811 (LiNi0.8Mn0.1Co0.1O2) cathode and mesocarbon microbeads anode active materials compared to conventional thick electrodes, allowing high‐mass loading (35.7 mg cm−2), 40% higher specific capacity, and 30% higher areal capacity after 200 cycles, high C‐rate performance, and longer cycle life.