Lithium film with abundant stepped structures: A promising route for homogeneous Li ion deposition to conquer lithium dendrite issue and its action mechanism

Abstract

Lithium is considered to be the “holy grail” for the application of energy storage due to its highest theoretical capacity and lowest anode potential. However, one of the grand difficulties in the development of lithium-based batteries is the lithium dendrite growth that leads to capacity fading and electrode degradation over long-term cycling. Compared with conventional electrolyte modifications, artificial solid electrolyte interfaces (SEI) synthesis and framework designing approaches, tuning surface morphology of lithium anode is the direct route to induce homogeneous Li ion deposition. Due to the high chemical activity of lithium metal, however, controllable growth of lithium micro/nanostructures by traditionally chemical approaches is still a big challenge. Herein, we have developed a facile compression route to fabricate lithium anode with abundant stepped lithium structures. The electrochemical results demonstrate that the dendritic growth issue is effectively suppressed by orderly arranged stepped lithium structures. After 90 cycles, a high discharge capacity of 954 mAh g−1 is achieved, which is 2.7 times that of the uncompressed lithium anode (342 mAh g−1). First-principles calculations reveal that the orderly arranged stepped lithium structures are lithiophilic active sites to adsorb Li ion, which contributes to homogeneous deposition of Li ion on lithium anode, eventually solving the lithium dendrite issue. This work paves a new road to suppress dendritic growth, which will provide some new ideas to design long recycling sodium, potassium and zinc, and other metal anode batteries.