Lithium metal batteries(LMBs)are considered the ideal next-generation high-energy-density systems,capable of surpassing the performance of lithium-ion batteries(LIBs).However,LMBs suffer from issues such as irreversib...Lithium metal batteries(LMBs)are considered the ideal next-generation high-energy-density systems,capable of surpassing the performance of lithium-ion batteries(LIBs).However,LMBs suffer from issues such as irreversible Li deposition/stripping,dendrite growth and significant volume fluctuations.Here,we use doctor blade coating to precisely control the loading of the bulk hard carbon(BHC)host with closed nanopores on carbon-coated copper(CCu)foil to achieve optimal cycling stability and rate performance for Li metal and anode-free battery systems.Through ex/in-situ techniques,we demonstrate that the BHC host induces a continuous intercalation-deposition mechanism,where the pre-lithiated BHC(preliBHC)phase,formed by Li+intercalation,improves Li affinity,accelerates Li+transport,and reduces nucleation overpotential,resulting in uniform Li deposition and effectively suppressing dendrite growth.Furthermore,these characterizations reveal that irreversible Li deintercalation from graphite layers is a key factor leading to the low initial Coulombic efficiency(ICE).Consequently,when coupled with a LiFePO_(4)cathode,the BHC-based full cell retains 96.3% of its capacity after 210 cycles at 1 C,demonstrating exceptional cycling stability.Notably,at-20℃,the full cell maintains 94.2% capacity retention after 60 cycles.These findings deepen the understanding of regulating Li metal deposition mechanisms and offer valuable insights into designing Li metal hosts for improved cycle life and high-rate performance.展开更多
基金supported by the National Key Research and Development Program of China(2022YFE0109400)Leading Edge Technology of Jiangsu Province(BK20220009,BK20232022)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Center for Microscopy and Analysis at Nanjing University of Aeronautics and Astronautics。
文摘Lithium metal batteries(LMBs)are considered the ideal next-generation high-energy-density systems,capable of surpassing the performance of lithium-ion batteries(LIBs).However,LMBs suffer from issues such as irreversible Li deposition/stripping,dendrite growth and significant volume fluctuations.Here,we use doctor blade coating to precisely control the loading of the bulk hard carbon(BHC)host with closed nanopores on carbon-coated copper(CCu)foil to achieve optimal cycling stability and rate performance for Li metal and anode-free battery systems.Through ex/in-situ techniques,we demonstrate that the BHC host induces a continuous intercalation-deposition mechanism,where the pre-lithiated BHC(preliBHC)phase,formed by Li+intercalation,improves Li affinity,accelerates Li+transport,and reduces nucleation overpotential,resulting in uniform Li deposition and effectively suppressing dendrite growth.Furthermore,these characterizations reveal that irreversible Li deintercalation from graphite layers is a key factor leading to the low initial Coulombic efficiency(ICE).Consequently,when coupled with a LiFePO_(4)cathode,the BHC-based full cell retains 96.3% of its capacity after 210 cycles at 1 C,demonstrating exceptional cycling stability.Notably,at-20℃,the full cell maintains 94.2% capacity retention after 60 cycles.These findings deepen the understanding of regulating Li metal deposition mechanisms and offer valuable insights into designing Li metal hosts for improved cycle life and high-rate performance.
