All-Solid-State Lithium Sulfur Cell Safety Characterization

Motivated by high theoretical specific capacity and inherent safety, this work investigates the performance of all-solid-state lithium-sulfur batteries (ASLBs) across increasing applied pressure and under electrical and mechanical abuse conditions. An all-PEEK (polyether ether ketone) split-cell holder with embedded temperature sensors was developed to provide a near-adiabatic test environment for measuring anode and cathode thermal response. Cells were fabricated, mechanically loaded, and electrically characterized, and then test-to-failure conditions were explored, including overcharge, short circuit, and nail puncture. The laboratory fabricated cell and newly developed split-cell holder with a sulfur loading of 3 g cm-2 demonstrated areal capacities greater than 3 mAh cm-2 at current densities of 0.5 mA cm-2, validating the cell holder's ability to operate across a range of applied pressures up to and including 60MPa. Increasing applied pressure showed recovery of lost cyclic capacity during constant pressure testing. Also, minimum anode/cathode thermal responses under test-to-failure conditions were measured, supporting a promising early look at the potential of this battery cell for use in safety-critical environments with low cycle life and high energy density requirements.