Yang Huicong, Liu Qingyun, Wang Yaozu, Ma Zhuoting, Tang Pei, Zhang Xiaoyin, Cheng Hui-Ming, Sun Zhenhua, Li Feng
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China.
Small. 2022 Jun;18(25):e2202349. doi: 10.1002/smll.202202349. Epub 2022 May 26.
Lithium metal is an ideal electrode material for future rechargeable batteries. However, dendrite formation and unstable solid electrolyte interphase film lead to safety concerns and poor Coulombic efficiency (CE). LiNO significantly improves the performance of the lithium metal anode in ester electrolytes but its use is restricted by low solubility. To increase the content of LiNO in the cell, a poly-(vinyl carbonate) organogel interlayer containing dissociated LiNO (LNO-PVC) is placed between the cathode and anode. The dissociated LiNO effectively increases the LiNO -release rate and compensates for the LiNO consumed in ester electrolytes during cycling. Via this interlayer, the performance of the lithium metal anode is significantly improved. The average CE of a Li-Cu cell reaches 98.6% at 0.5 mA cm -1 h and 98.5% at 1 mA cm -1 h for 300 cycles. Also, a Li||NCM811 pouch cell with LNO-PVC interlayer can also reach a 400 Wh kg energy density with a cycling life of 65 cycles. This strategy sheds light on the effect of the state of this salt on its release/dissolution kinetics, which is determined by the interactions between the salt and host material.
锂金属是未来可充电电池的理想电极材料。然而，枝晶的形成和不稳定的固体电解质界面膜导致安全问题和较差的库仑效率（CE）。LiNO显著改善了锂金属阳极在酯类电解质中的性能，但其应用受到低溶解度的限制。为了增加电池中LiNO的含量，在阴极和阳极之间放置了一层含有离解LiNO的聚（碳酸乙烯酯）有机凝胶中间层（LNO-PVC）。离解的LiNO有效地提高了LiNO的释放速率，并补偿了循环过程中酯类电解质中消耗的LiNO。通过这种中间层，锂金属阳极的性能得到了显著改善。Li-Cu电池在0.5 mA cm-2下循环300次时，平均CE达到98.6%，在1 mA cm-2下循环300次时，平均CE达到98.5%。此外，带有LNO-PVC中间层的Li||NCM811软包电池在循环寿命为65次时，能量密度也能达到400 Wh kg-1。该策略揭示了这种盐的状态对其释放/溶解动力学的影响，这是由盐与主体材料之间的相互作用决定的。
