Polyimide as a durable cathode for all-solid-state Li(Na)-organic batteries with boosted cell-level energy density

The integration of organic electrode materials (OEMs) with solid-state electrolytes (SSEs) is expected to build an all-solid-state battery (ASSB) with long-term sustainability, high safety, and high energy density. Despite this great promise, the cell-level energy density is still far from practically applicable, which stems from the ultrathick SSE layer and thin cathode layer used in a pellet-type ASSB design. Here, a cost-effective polyimide (PI) material was first exploited as an organic cathode for sulfide-based ASSBs. A capacity of ~190 mAh g(-1) was delivered with almost no capacity decay over 300 cycles. Moreover, for the first time, a dry-film approach was introduced to manufacture a sheet-type Li-organic ASSB with an ultrathin SSE layer and a high-areal-loading PI cathode. Notably, PI is a perfect candidate for dry-film technology due to its high thermal stability and extraordinary chemical inertness toward sulfide SSEs. Remarkably, the free-standing SSE membrane was merely 46 mu m thick, and an ultralow areal resistance of 3.3 & UOmega; cm(2) was achieved, more than tenfold lower than that of reported SSE pellets. One order of magnitude boost in the cell-level energy density was achieved. This work presents a significant leap in transferring organic ASSB technology from laboratory research to factory manufacturing.

Automated summary

This study successfully utilized polyimide material as an organic cathode to manufacture an all-solid-state battery with high energy density and stability. By introducing a dry-film approach, an ultrathin solid-state electrolyte layer and high-area organic cathode were achieved, significantly improving the cell-level energy density.