摘要
高比容量、高能量密度锂金属负极的应用受到了电池循环过程中锂枝晶不规则生长的限制.本文通过在表面修饰纳米锌的3D碳布框架中熔融浸润锂金属制备成复合锂金属负极.利用电化学沉积在物理化学性质稳定的离子液体中对碳布修饰锌纳米层.在高温下,将熔融锂浸入碳布-纳米锌的框架制备出复合的锂金属负极.稳定的框架主体降低了有效电流密度和界面电阻,诱导锂的均匀生长,抑制了锂枝晶的形成和生长,因此缓解了锂负极的体积膨胀和粉化情况.基于以上原因,3D碳布-锌-锂金属复合负极组成的对称电池表现出了较低的过电势和长循环稳定性.在锂金属/磷酸铁锂全电池中展示出了超长的电化学循环稳定性.
The application of lithium metal anode with high specific capacity and energy density is limited by the volume expansion and pulverization caused by dendrite growth during cycle process.We propose a composite lithium anode by immersing molten lithium on the flexible three-dimensional(3D)carbon cloth scaffold with the zinc nanoparticles.The lithiophilic zinc nanoparticles layer of framework is synthesized by fast and easy electrochemical deposition from ionic liquid avoiding high temperature,high pressure and toxic reagent.The lithium is infused into the 3D lithiophilic framework,the composite anode is obtained.The steady network structure can confine the lithium and lead to Li dendrite restraining and reducing volume change due to the low interfacial resistance and reduce the effective current density,which induced the homogeneous Li growth.Benefiting from this,the Li infused 3D carbon cloth-Zn symmetric battery exhibits a low stripping/plating overpotential(~30 mV)and can be stable over 900 h at 1 mA cm-2.The Li//LiFePO4 battery delivers higher reversible capacity(140 mAh g^-1 at 2 C and 120 mAh g^-1 at 5 C)and stable cycling for 1500 and 2000 cycles than bare Li.
基金
supported partially by the National Natural Science Foundation of China (51973171, 51873170)
the Young Talent Support Plan of Xi’an Jiaotong University。
