Tuning Ion/Electron Conducting Properties at Electrified Interfaces for Practical All-Solid-State Li-Metal Batteries

Poly(ethylene oxide) (PEO) based solid-state electrolytes with good chemical stability against Li-metal, provide a promising solution for practical all solid-state Li-metal batteries (ASSLMBs). However, the risk of short circuit using thin PEO under semi-molten state and the oxidative decomposition of PEO by cathodes under high voltage hinder the practical application of PEO-based ASSLMBs. Here, it is found that by readjusting the Li+ and e(-) conductivity at anode/cathode interface by introducing Nanodiamonds (NDs) into PEO electrolytes can greatly improve the electrochemical performance of PEO-based batteries. Under the mediation of high modulus and insulative NDs, the lifespan of Li symmetric cells can increase by 30 times at 0.8 mA cm(-2), and high-voltage Li/LiCoO2 cells show excellent capacity retention under practical testing conditions (50 mu m Li and 30 mu m PEO electrolyte).

Automated summary

Poly(ethylene oxide) (PEO) based solid-state electrolytes show potential for practical all solid-state Li-metal batteries (ASSLMBs) due to their good chemical stability. However, the use of thin PEO presents a risk of short circuit in its semi-molten state, and PEO can be oxidatively decomposed by cathodes under high voltage, hindering the practical application of PEO-based ASSLMBs. In this study, the introduction of Nanodiamonds (NDs) into PEO electrolytes is found to greatly improve the electrochemical performance of PEO-based batteries by readjusting the Li+ and e(-) conductivity at the anode/cathode interface.