Electrophoretic Deposited Black Phosphorus on 3D Porous Current Collectors to Regulate Li Nucleation for Dendrite-Free Lithium Metal Anodes.

Li metal is considered a highly desirable anode for next-generation high-energy-density rechargeable lithium batteries. However, irregular Li dendrite formation and infinite relative volume changes prevent the commercial adoption of Li-metal anodes. Here, electrophoretic deposition of black phosphorus (BP) on commercial Cu foam (BP@Cu foam) is reported to regulate Li nucleation for the first time. First-principles calculations reveal that the unique two-dimensional (2D) structure of BP is beneficial to Li intercalation and propagation. Compared with the random Li nucleation and growth on bare Cu foam, Li ions are preferably confined into the BP layers, which induces uniform Li nucleation at the early stage of the Li deposition and guides the following lateral Li growth on BP@Cu foam. In addition, the three-dimensional (3D) porous and conductive framework of Cu foams further mitigate the volume change and dissipate the current density. Attributing to these merits, the BP@Cu foam exhibits significantly enhanced Coulombic efficiency and cycling stability compared with bare Cu foam. In the full-cell configuration paired with a Li4Ti5O12 or LiFePO4 cathode, the BP@Cu foam also boosts the battery performances. This work provides new insights into the development of BP and other elaborate 2D materials for achieving dendrite-free Li-metal anodes.

Three-Dimensional Branched TiO2 Architectures in Controllable Bloom for Advanced Lithium-Ion Batteries.

Three-dimensional branched TiO2 architectures (3D BTA) with controllable morphologies were synthesized via a facile template-free one-pot solvothermal route. The volume ratio of deionized water (DI water) and diethylene glycol in solvothermal process is key to the formation of 3D BTA assembled by nanowire-coated TiO2 dendrites, which combines the advantages of 3D hierarchical structure and 1D nanoscale building blocks. Benefiting from such unique structural features, the BTA in full bloom achieved significantly increased specific surface areas and shortened Li(+) ion/electrons diffusion pathway. The lithium-ion batteries based on BTA in full bloom exhibited remarkably enhanced reversible specific capacity and rate performance, attributing to the high contact area with the electrolyte and the short solid state diffusion pathway for Li(+) ion/electrons promoting lithium insertion and extraction.