A low-temperature aqueous solution synthesis of nanostructured one-dimensional (1D) molybdenum trioxide (MoO₃) was developed. The subsequent self-assembly of the fibers to form large-scale freestanding films was achieved without any assistance of organic compounds. Indeed, the whole process, from synthesis to assembly, does not require toxic organic solvents. As an example of the application of our synthesized materials, we built two types of half-cell lithium-ion batteries: (i) the cathode made out of 1D MoO ₃, having the width in 50-100 nm, with the length in micro scale, and with thickness in ∼10 nm, and (ii) the anode made out of the macroscopic oxide papers consisting of 1D MoO₃ and carbon materials. As a cathode material, 1D MoO₃ showed a high rate capability with a stable cycle performance up to 20 A g^-1 as a result of a short Li⁺ diffusion path along the [101] direction and less grain boundaries. As an anode material, the composite paper compound showed a first specific discharge capacity of 800 mAh g^-1. These findings indicate not only an affordable, eco-efficient synthesis and assembly of nanomaterials but also show a new attractive strategy toward a possible full aqueous process for a large-scale fabrication of freestanding oxide paper compounds without any toxic organic solvent.