Field-Assisted Regulation Induced by Cobalt-Doped ZnO for Dendrite-Free Lithium Metal Anodes.

Lithium metal batteries are deemed as an optimal candidate for the next generation of durable energy storage devices. However, the growth of lithium dendrite and significant volume expansion pose as obstacles that impede the application of lithium metal batteries. In this work, a functional copper current collector was designed by coating it with Co-doped ZnO (Co/ZnO) to enhance the lithiophilicity through local electric fields and built-in magnetic fields induced by the ferromagnetic material. The incorporation of Co not only induces a local electric field and thus accelerating electron transfer, but also imparts the ferromagnetic behavior to ZnO, resulting in an internal magnetic field to regulate the dynamic trajectory. Profiting from the above advantages, the symmetric cells have excellent cycle stability in 1 mA cm-2 and 1 mAh cm-2 , maintaining ultra-low voltage for over 2000 h. This study provides a realizable pathway for next-generation current collector of copper modification.

A Highly-Lithiophilic Mn3O4/ZnO-Modified Carbon Nanotube Film for Dendrite-Free Lithium Metal Anodes.

Lithium metal anode is deemed as a potential candidate for high energy density batteries, which has attracted increasing attention. Unfortunately, Li metal anode suffers from issues such as dendrite grown and volume expansion during cycling, which hinders its commercialization. Herein, we designed a porous and flexible self-supporting film comprising of single-walled carbon nanotube (SWCNT) modified with a highly-lithiophilic heterostructure (Mn3O4/ZnO@SWCNT) as the host material for Li metal anodes. The p-n-type heterojunction constructed by Mn3O4 and ZnO generates a built-in electric field that facilitates electron transfer and Li+ migration. Additionally, the lithiophilic Mn3O4/ZnO particles serve as the pre-implanted nucleation sites, dramatically reducing the lithium nucleation barrier due to their strong binding energy with lithium atoms. Moreover, the interwoven SWCNT conductive network effectively lowers the local current density and alleviates the tremendous volume expansion during cycling. Thanks to the aforementioned synergy, the symmetric cell composed of Mn3O4/ZnO@SWCNT-Li can stably maintain a low potential for more than 2500 h at 1 mA cm-2 and 1 mAh cm-2. Furthermore, the Li-S full battery composed of Mn3O4/ZnO@SWCNT-Li also shows excellent cycle stability. These results demonstrate that Mn3O4/ZnO@SWCNT has great potential as a dendrite-free Li metal host material.