Solvation-Mediated Free Energy Stabilization Enables Li/CF_x Pouch Cells Over 800 Wh kg^-1 via Minimizing Heat...

Maximizing electrochemical energy conversion efficiency requires minimizing parasitic heat release. Li/CF_x batteries, despite their high theoretical energy density (>2100 Wh kg^-1), suffer from severe voltage loss and thermal accumulation that compromise both performance and safety. Here, we identify that parasitic decomposition of a metastable intermediate phase (C[F^-·Li⁺·Sol_n]) constitutes the primary energy loss pathway that dissipates chemical energy as heat instead of electricity. By introducing a solvation-mediated Gibbs free energy stabilization strategy via strengthening the Li⁺-solvent interaction, we delay the premature decomposition of C[F^-·Li⁺·Sol_n] intermediate and promote the conversion of chemical energy to electrical output. This approach reduces heat generation by 39.6% and elevates the discharge voltage from 2.50-2.92 V. Practical multi-ampere-hour pouch cells (6-20 Ah) achieve stable discharge plateaus near 2.90 V and record cell-level energy densities of 816-830 Wh kg^{- 1}. This work establishes a thermodynamic paradigm of solvation-mediated free-energy tuning for high-energy-density Li/CF_x battery technologies.