A Si/rGO/SiOC composite is designed using hydrophobic rGO for uniform distribution of Si in SiOC matrix. rGO contributed to the improvement of electrical conductivity, and the volume expansion of Si was effectively alleviated by the SiOC material.

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Summary The formation of Li4SiO4 (LSO) coating layer on LiNi0.88Co0.05Mn0.07O2 (LNCM) was achieved by incorporating a new tetraethyl orthosilicate (TEOS)‐dropping coating method. This concept includes the hydrolysis reaction of TEOS on the surface of Ni0.88Co0.05Mn0.07(OH)2 and the subsequent calcination process with lithium source to obtain LSO‐coated LNCM cathode materials successfully during the calcination process. This method provides the driving force for the formation of a more uniform and thin coating layer compared with the traditional wet‐chemical coating method. The bare LNCM and LSO‐coated LNCM showed similar capacity retention rates during room temperature (25°C) cycling, but the capacity retention of LSO‐LNCM (81.6% after 100 cycles) for the cycling test at elevated temperature was significantly increased compared with bare LNCM (63.69% after 100 cycles). Additionally, the Li‐ion accessibility of the coated LNCM electrode was improved by the existence of the Li‐containing coating materials, and the results of analysis by the galvanostatic intermittent titration technique (GITT) confirmed the better Li‐ion diffusivity of the coated sample. These results indicate the high possibility of this novel coating method for application in various materials for developing secondary batteries.

Li metal is regarded as an ultimate anode material for highenergy-density lithium-ion batteries; however, addressing dendritic deposition and large volume changes during cycling is essential to commercialize the Li metal anodes. Herein, we propose Ag-embedded N-doped carbon/Li-ion conductor double-shelled hollow spheres (Ag@NC@LAZP) as an electrode material for selective Li deposition. When constructing hollow spheres for Li storage, the use of lithiophilic Ag nanoseeds and N-doped carbon (NC) layers lowers the nucleation overpotential, thereby facilitating uniform Li deposition. However, if the lithiophilic NC layer is exposed outside the hollow spheres, Li may grow outside the hollow spheres. Therefore, the application of a Li 1.5 Al 0.5 Zr 1.5 (PO 4 ) 3 (LAZP) outer layer is effective for the complete deposition of Li into the spherical inner space by blocking the exposed lithiophilic sites. The stable Li plating/stripping of the Ag@NC@LAZP electrode was achieved by the Li-ion conductive LAZP outer layer, and accordingly, dendritic growth was eliminated and improved cycling with 98.2% Coulombic efficiency for more than 450 cycles was observed. Covering lithiophilic sites and guiding Li deposition through the Li-ion conductive layer are effective for achieving stable Li metal anodes.

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