Self-healing, Improved Efficiency Solid State Rechargeable Li/I₂ Based Battery

Solid state electrolytes are receiving significant interest due to the prospect of improved safety, however, addressing the incidence and consequence of internal short circuits remains an important issue. Herein, a battery based on a LiI-LiI(HPN)₂ solid state electrolyte demonstrated self-healing after internal shorting where the cells recovered and continued to cycle effectively. The functional rechargeable electrochemistry of the self-forming Li/I₂-based battery was investigated through interfacial modification by inclusion of Li metal (at the negative interface), and/or fabricated carbon nanotube substrates at the positive interface. A cell design with lithium metal at the negative and a carbon substrate at the positive interface produced Coulombic efficiencies > 90% over 60 cycles. Finally, the beneficial effects of moderately elevated temperature were established where a 10°C temperature increase led to ~5X lower resistance.