Effective electron-ion percolation network enabled by in situ lithiation for dendrite-free Li metal battery

The development of a lithium metal anode has been hindered by the problem of lithium dendrites. The fast and homogeneous ion transport to achieve even lithium plating is challenging but still remains elusive. Improving the single conduction of ions or electrons is not enough to achieve dendrite-free and long life Li-metal composite electrodes. Herein, we use in situ lithiation and electroplating methods to construct an effective mixed electron-ion percolation network composite anode. The mixed ion-electron conductive framework can build a stable interface that provides nucleation sites for Li plating. At the same time, the 3D percolation network composed of 3D nanosheets can facilitate the fast transport of ions and electrons, enabling uniform lithium plating inside the skeleton. As a result, the composite anodes exhibit a stable dendrite-free Li stripping/plating process with low overpotential. Furthermore, the full cell using the composite anode coupled with the LiFePO4 cathode displays high cycle stability with a capacity retention rate of about 100% after 500 cycles. The present strategy of the mixed ion-electron conductive skeleton could further promote the development of the next-generation lithium metal anode.