Thickness-controllable Li-Zn composite anode for high-energy and low-N/P ratio lithium metal batteries

作者：Li, Xueyang; Zhu, Renjie; Jiang, Haojie; Yu, Yue; Wan, Wang; Li, Xinglong; Wang, Chao^*; Huang, Yunhui^*

来源：Journal of Materials Chemistry A, 2022, 10(20): 11246-11253.

DOI：10.1039/d2ta02162e

• SOLID-ELECTROLYTE INTERPHASE
• HIGH AREAL CAPACITY
• CONDUCTING SCAFFOLD
• ALLOY
• PHASE
• DEPOSITION
• ZINC

Lithium metal anode (LMA) is considered the most promising candidate for energy-dense batteries and is widely employed for its extremely high gravimetric capacity (3860 mA h g(-1)) and volumetric capacity (2060 mA h cm(-3)) and the lowest redox potential (-3.04 V vs. SHE). However, the commercialization of LMA has been prevented by the interior lithium morphology instability and high N/P ratio on the exterior. Lithium morphology instability leads to poor cycling performance and security risks, while the high N/P ratio results in the low true specific capacity of LMAs and low energy density of pouch cells. In order to solve these two issues, we developed a thickness-controllable lithium-zinc composite anode consisting of beta-Li and the intermetallic LiZn compound by roll-to-roll pressing, which allowed the preparation of a thin Li-Zn foil (20 mu m). The rod-like LiZn compound acted as a 3D mixed-ion and electron conductor (MIEC) skeleton that offers a large number of binding sites for Li adatoms, thus achieving morphological stability, less consumption of the liquid electrolyte and cyclable lithium. On this foundation, the Li-Zn composite achieved better electrochemical performance during the plating and stripping process with a lower overpotential. Furthermore, coin cells with a LiFePO4 cathode and the Li-Zn anode exhibited 1.6 times the cycling life of those with LMAs. The high-capacity NCM811 pouch cell with an N/P ratio of 1 achieved 50 stable cycles with the Li-Zn anode, and the energy density was up to 357 Wh kg(-1) and 1223 Wh L-1.

• 单位
  华中科技大学; 同济大学