Yan Congcong, Xu Tingting, Ma Caiyun, Zang Jinhao, Xu Junmin, Shi Yumeng, Kong Dezhi, Ke Chang, Li Xinjian, Wang Ye
Key Laboratory of Material Physics of Ministry of Education, School of Physics and Engineering, Zhengzhou University, Zhengzhou, China.
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China.
Front Chem. 2019 Oct 25;7:714. doi: 10.3389/fchem.2019.00714. eCollection 2019.
Lithium metal is deemed as an ideal anode material for next-generation lithium ion batteries (LIBs) due to its high specific capacity and low redox potential. However, uncontrolled lithium dendrite formation during electrochemical deposition leads to a low Coulombic efficiency and serious safety issues, dragging metallic lithium anodes out of practical application. One promising strategy to suppress lithium dendrite issues is employing a three-dimensional host with admirable conductivity and large surface area. Herein, a vertical graphene nanosheet grown on carbon cloth (VG/CC) synthesized is adopted as the Li deposition host. The three-dimensional VG/CC with a large surface area can provide abundant active nucleation sites and effectively reduce the current density, leading to homogeneous Li deposition to overcome the dendrite issue. The Li@VG/CC anode exhibits a dendrite-free morphology after a long cycle and superior electrochemical performance to that of planar Cu current collector. It delivers a small voltage hysteresis of 90.9 mV at a high current density of 10 mA cm and a Coulombic efficiency of 99% over 100 cycles at 2 mA cm. Our results indicate that this all-carbon-based nanostructure host has great potential for next-generation Li metal batteries.
锂金属因其高比容量和低氧化还原电位，被视为下一代锂离子电池（LIBs）的理想负极材料。然而，电化学沉积过程中不受控制的锂枝晶形成会导致库仑效率低下和严重的安全问题，使金属锂负极无法实际应用。抑制锂枝晶问题的一种有前景的策略是采用具有良好导电性和大表面积的三维主体材料。在此，合成的生长在碳布上的垂直石墨烯纳米片（VG/CC）被用作锂沉积主体。具有大表面积的三维VG/CC可以提供丰富的活性成核位点，并有效降低电流密度，从而实现均匀的锂沉积，克服枝晶问题。经过长时间循环后，Li@VG/CC负极呈现无枝晶形态，并且电化学性能优于平面铜集流体。在10 mA cm的高电流密度下，它具有90.9 mV的小电压滞后，在2 mA cm下100次循环的库仑效率为99%。我们的结果表明，这种全碳基纳米结构主体在下一代锂金属电池中具有巨大潜力。
