TY - JOUR
T1 - CNT/PVDF Composite Coating Layer on Cu with a Synergy of Uniform Current Distribution and Stress Releasing for Improving Reversible Li Plating/Stripping
AU - Guo, Qiang
AU - Yu, Yanan
AU - Xia, Shengjie
AU - Shen, Cai
AU - Hu, Di
AU - Deng, Wei
AU - Dong, Daojie
AU - Zhou, Xufeng
AU - Chen, George Zheng
AU - Liu, Zhaoping
N1 - Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/10/12
Y1 - 2022/10/12
N2 - The uncontrollable formation of polymorphous Li deposits, e.g., whiskers, mosses, or dendrites resulting from nonuniform interfacial current distribution and internal stress release in the upward direction on the conventional current collector (e.g., Cu foil) of Li metal rechargeable batteries with a lithium-metal-free negatrode (LMFRBs), leads to rapid performance degradation or serious safety problems. The 3D carbon nanotubes (CNTs) skeleton has been proven to effectively reduce the current density and eliminate the internal accumulated stress. However, remarkable electrolyte decomposition, inherent Li source consumption due to repeated SEI formation, and Li+ intercalation in CNTs limit the application of 3D CNTs skeleton. Thus, it is necessary to avoid the side effects of the 3D CNTs skeleton and retain uniform interfacial current distribution and stress mitigation. In this work, we integrate the CNTs network with a soft functional polymer polyvinylidene fluoride (PVDF) to form a relatively dense coating layer on Cu foil, which can shield the contact between the internal surface of the 3D CNTs framework and the electrolyte. Simultaneously, the Li-F-rich SEI resulting from the partial reduction of PVDF with deposited Li and the soft nature of the coating layer release the accumulation of internal stress in the horizontal direction, resulting in mosses/whisker-free Li deposition. Thus, improved Li deposition/dissolution and stable cycling performance of the LMFRBs can be achieved.
AB - The uncontrollable formation of polymorphous Li deposits, e.g., whiskers, mosses, or dendrites resulting from nonuniform interfacial current distribution and internal stress release in the upward direction on the conventional current collector (e.g., Cu foil) of Li metal rechargeable batteries with a lithium-metal-free negatrode (LMFRBs), leads to rapid performance degradation or serious safety problems. The 3D carbon nanotubes (CNTs) skeleton has been proven to effectively reduce the current density and eliminate the internal accumulated stress. However, remarkable electrolyte decomposition, inherent Li source consumption due to repeated SEI formation, and Li+ intercalation in CNTs limit the application of 3D CNTs skeleton. Thus, it is necessary to avoid the side effects of the 3D CNTs skeleton and retain uniform interfacial current distribution and stress mitigation. In this work, we integrate the CNTs network with a soft functional polymer polyvinylidene fluoride (PVDF) to form a relatively dense coating layer on Cu foil, which can shield the contact between the internal surface of the 3D CNTs framework and the electrolyte. Simultaneously, the Li-F-rich SEI resulting from the partial reduction of PVDF with deposited Li and the soft nature of the coating layer release the accumulation of internal stress in the horizontal direction, resulting in mosses/whisker-free Li deposition. Thus, improved Li deposition/dissolution and stable cycling performance of the LMFRBs can be achieved.
KW - carbon nanotubes
KW - polyvinylidene fluoride
KW - current distribution
KW - stress release
KW - Li metal rechargeable batteries with a lithium-metal-free negatrode
UR - https://doi.org/10.1021/acsami.2c13193
U2 - 10.1021/acsami.2c13193
DO - 10.1021/acsami.2c13193
M3 - Article
C2 - 36174108
SN - 1944-8244
VL - 14
SP - 46043
EP - 46055
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 40
ER -