Popcorn-like niobium oxide with cloned hierarchical architecture as advanced anode for solid-state lithium ion batteries

The advancement of high-power solid-state lithium ion batteries (LIBs) is closely in connection with the breakthrough of electrode materials. In this work, for the first time, we report a popcorn-like niobium oxide with cloned hierarchical architecture via sacrificial puffed rice carbon (PRC) template and solvothermal method. The popcorn-like Nb2O5 (PL-Nb2O5) shows a tertiary hierarchical macrocellular structure with cross-linked 2D secondary Nb2O5 nanoflakes, which are composed of primary self-assembled Nb2O5 nanocrystals. Impressively, this exquisite hierarchical architecture offers continuous fast transport paths for ion/electron and improves the specific surface area & porosity, resulting in accelerated reaction kinetics and good compatibility with gel polymer electrolyte (GPE). Accordingly, the popcorn-like Nb2O5 electrode is endowed with superior lithium ion storage performance in gel polymer electrolyte with good high-rate capacities (126 mA h g-1 at 5C and 103 mA h g-1 at 10C) and stable long-term cycling performance (75 mA h g-1 after 1000 cycles at 5C). Our findings propose a new bioinspired template way for construction of cloned metal oxides architectures for solid-state energy storage systems.