Article

A Paradigm of Calendaring‐Driven Electrode Microstructure for Balanced Battery Energy Density and Power Density

Renming ZhanWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaDongsheng RenInstitute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 P. R. ChinaShiyu LiuWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaZhengxu ChenWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaXuerui LiuWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaWenyu WangWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaLin FuWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaXiancheng WangWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaShuibin TuWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaYangtao OuWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaHanlong GeWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 ChinaAndrew Jun Yao WongInstitute of Materials Research and Engineering Agency for Science Technology and Research (A*STAR) Singapore 138634 SingaporeZhi Wei SehInstitute of Materials Research and Engineering Agency for Science Technology and Research (A*STAR) Singapore 138634 SingaporeLi WangInstitute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 P. R. ChinaYongming SunWuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China

2022en

ABI

Abstract

Abstract The microstructure of an electrode plays a critical role in the electrochemical performance of lithium‐ion batteries, including the energy and power density. Using a micrometer‐scale Wadsley–Roth phase TiNb 2 O 7 active material with Li intercalation chemistry as a model system, the relationship between electrochemical performance and microstructure of calendared electrodes with same mass loading but different electrode parameters is studied by both experimental investigation and theoretical modeling, providing a paradigm of calendaring‐driven electrode microstructure for balanced battery energy density and power density. Along with the reduction in porosity, ion and electron diffusion distance decreases, which is beneficial for charge transfer and rate capability. Nevertheless, the narrowed ion diffusion pathway increases the resistance for ion diffusion. The rate capability, volumetric capacity, and materials utilization are thus predominantly restricted by the microstructures of the electrode, providing fundamental insights into electrode microstructure design for different applications. As an example, an optimized TiNb 2 O 7 electrode with compaction density of ≈2.5 g cm ‐3 and mass loading of ≈8.5 mg cm ‐2 provides the highest specific charge capacity of 271.3 mAh g ‐1 at 0.2 C in half cell configuration and 70.4% capacity retention at 6 C in full configuration, enabling balanced energy density and power density of batteries.

Identifiers

DOI: 10.1002/aenm.202202544

Citations and references

Cited by 20 references

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