A Unified Synthesis Framework for Zr_{0.75}Ca_{0.25}Li_2B_4H_{3.5}F_{0.2}O_{0.3} Across (Superconductivity, Solid-State Lithium Battery Electrolytes and Hydrogen Energy Storage)

Abstract The realization of near-ambient room-temperature superconductivity (RTSC) and next-generation energy storage is fundamentally bottlenecked by extreme physical pressure requirements and thermodynamic phase instabilities. This theoretical framework introduces the Qindra-Core design, an engineered complex doped borohydride formulated as Zr_{0.75}Ca_{0.25}Li_2B_4H_{3.5}F_{0.2}O_{0.3}. By utilizing heavy-cation (Zr^{4+}, Ca^{2+}) substitution to induce internal chemical pre-compression, the required external pressure for the stabilization of the high-symmetry covalent B-H metallic network is theorized to drop below 5 GPa. Furthermore, fractional electronegative doping (F, O) is utilized to tune the Fermi level, maximizing electron-phonon coupling (\lambda). To bypass the thermodynamic instability inherent in such highly energetic states, we propose a unified, solvent-free mechanochemical metathesis synthesis route governed by rapid-quench kinetic trapping. Depending on the final operating pressures, this single synthetic pipeline can be utilized to lock the lattice into specific metastable states for three distinct applications: a near-ambient RTSC (<5\text{ GPa}), a superionic solid-state battery electrolyte (ambient pressure), or a low-temperature solid-state hydrogen storage medium (1-10\text{ MPa}). A comprehensive computational roadmap for validation via Density Functional Theory (DFT) and Special Quasirandom Structures (SQS) is also provided.