The crystal phase structure of cathode material plays an important role in the cell performance. ... more The crystal phase structure of cathode material plays an important role in the cell performance. During cycling, the cathode material experiences immense stress due to phase transformation, resulting in capacity degradation. Here, we show phase-engineered VO2 as an improved potassium-ion battery cathode; specifically, the amorphous VO2 exhibits superior K storage ability, while the crystalline M phase VO2 cannot even store K+ ions stably. In contrast to other crystal phases, amorphous VO2 exhibits alleviated volume variation and improved electrochemical performance, leading to a maximum capacity of 111 mAh g−1 delivered at 20 mA g−1 and over 8 months of operation with good coulombic efficiency at 100 mA g−1. The capacity retention reaches 80% after 8500 cycles at 500 mA g−1. This work illustrates the effectiveness and superiority of phase engineering and provides meaningful insights into material optimization for rechargeable batteries.
Lithium metal has emerged as the most prospective candidate for the realization of improved batte... more Lithium metal has emerged as the most prospective candidate for the realization of improved battery systems. However, notorious Li dendrite formation and the huge volume effect during cycling critically impair the further practical deployment of Li metal batteries. Herein, we propose hierarchical Ni-and Co-based oxynitride (NiCoO 2 /CoO/Ni 3 N) nanoarrays with superior lithiophilicity on a three-dimensional nickel foam (NiCoON/NF) as a host for highly stable Li metal anodes. The uniform nitrogen-infused nanorod-on-nanosheet arrays present improved electrical conductivity and an increased concentration of active sites with oxygen vacancies to enhance the surface lithiophilicity, which effectively facilitates homogeneous Li nucleation/growth. Moreover, the hyperbranched structure can induce a homogeneous distribution of Li-ion flux, owing to the enlarged surface area, thereby providing sufficient space to store deposited lithium and relieve the volume expansion. Consequently, the NiCoON/NF host delivers a high Coulombic efficiency (98.4% over 600 cycles) at 1 mA cm-2 and an ultralong lifespan (> 2000 h) under a high capacity of 3 mAh cm-2. Remarkably, a Li@NiCoON/NF-LiFePO 4 full battery also reveals impressive electrochemical performance. This work demonstrates new insights into safe rechargeable Li metal batteries.
Lithium metal has emerged as the most prospective candidate for the realization of improved batte... more Lithium metal has emerged as the most prospective candidate for the realization of improved battery systems. However, notorious Li dendrite formation and the huge volume effect during cycling critically impair the further practical deployment of Li metal batteries. Herein, we propose hierarchical Ni-and Co-based oxynitride (NiCoO 2 /CoO/Ni 3 N) nanoarrays with superior lithiophilicity on a three-dimensional nickel foam (NiCoON/NF) as a host for highly stable Li metal anodes. The uniform nitrogen-infused nanorod-on-nanosheet arrays present improved electrical conductivity and an increased concentration of active sites with oxygen vacancies to enhance the surface lithiophilicity, which effectively facilitates homogeneous Li nucleation/growth. Moreover, the hyperbranched structure can induce a homogeneous distribution of Li-ion flux, owing to the enlarged surface area, thereby providing sufficient space to store deposited lithium and relieve the volume expansion. Consequently, the NiCoON/NF host delivers a high Coulombic efficiency (98.4% over 600 cycles) at 1 mA cm-2 and an ultralong lifespan (> 2000 h) under a high capacity of 3 mAh cm-2. Remarkably, a Li@NiCoON/NF-LiFePO 4 full battery also reveals impressive electrochemical performance. This work demonstrates new insights into safe rechargeable Li metal batteries.
The crystal phase structure of cathode material plays an important role in the cell performance. ... more The crystal phase structure of cathode material plays an important role in the cell performance. During cycling, the cathode material experiences immense stress due to phase transformation, resulting in capacity degradation. Here, we show phase-engineered VO2 as an improved potassium-ion battery cathode; specifically, the amorphous VO2 exhibits superior K storage ability, while the crystalline M phase VO2 cannot even store K+ ions stably. In contrast to other crystal phases, amorphous VO2 exhibits alleviated volume variation and improved electrochemical performance, leading to a maximum capacity of 111 mAh g−1 delivered at 20 mA g−1 and over 8 months of operation with good coulombic efficiency at 100 mA g−1. The capacity retention reaches 80% after 8500 cycles at 500 mA g−1. This work illustrates the effectiveness and superiority of phase engineering and provides meaningful insights into material optimization for rechargeable batteries.
Lithium metal has emerged as the most prospective candidate for the realization of improved batte... more Lithium metal has emerged as the most prospective candidate for the realization of improved battery systems. However, notorious Li dendrite formation and the huge volume effect during cycling critically impair the further practical deployment of Li metal batteries. Herein, we propose hierarchical Ni-and Co-based oxynitride (NiCoO 2 /CoO/Ni 3 N) nanoarrays with superior lithiophilicity on a three-dimensional nickel foam (NiCoON/NF) as a host for highly stable Li metal anodes. The uniform nitrogen-infused nanorod-on-nanosheet arrays present improved electrical conductivity and an increased concentration of active sites with oxygen vacancies to enhance the surface lithiophilicity, which effectively facilitates homogeneous Li nucleation/growth. Moreover, the hyperbranched structure can induce a homogeneous distribution of Li-ion flux, owing to the enlarged surface area, thereby providing sufficient space to store deposited lithium and relieve the volume expansion. Consequently, the NiCoON/NF host delivers a high Coulombic efficiency (98.4% over 600 cycles) at 1 mA cm-2 and an ultralong lifespan (> 2000 h) under a high capacity of 3 mAh cm-2. Remarkably, a Li@NiCoON/NF-LiFePO 4 full battery also reveals impressive electrochemical performance. This work demonstrates new insights into safe rechargeable Li metal batteries.
Lithium metal has emerged as the most prospective candidate for the realization of improved batte... more Lithium metal has emerged as the most prospective candidate for the realization of improved battery systems. However, notorious Li dendrite formation and the huge volume effect during cycling critically impair the further practical deployment of Li metal batteries. Herein, we propose hierarchical Ni-and Co-based oxynitride (NiCoO 2 /CoO/Ni 3 N) nanoarrays with superior lithiophilicity on a three-dimensional nickel foam (NiCoON/NF) as a host for highly stable Li metal anodes. The uniform nitrogen-infused nanorod-on-nanosheet arrays present improved electrical conductivity and an increased concentration of active sites with oxygen vacancies to enhance the surface lithiophilicity, which effectively facilitates homogeneous Li nucleation/growth. Moreover, the hyperbranched structure can induce a homogeneous distribution of Li-ion flux, owing to the enlarged surface area, thereby providing sufficient space to store deposited lithium and relieve the volume expansion. Consequently, the NiCoON/NF host delivers a high Coulombic efficiency (98.4% over 600 cycles) at 1 mA cm-2 and an ultralong lifespan (> 2000 h) under a high capacity of 3 mAh cm-2. Remarkably, a Li@NiCoON/NF-LiFePO 4 full battery also reveals impressive electrochemical performance. This work demonstrates new insights into safe rechargeable Li metal batteries.
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Papers by Jian Zhu