Search

LiNixCoyMnzO2 (x+y+z=1)||graphite lithium‐ion battery (LIB) chemistry promises practical applications. However, its low‐temperature (≤ −20 °C) performance is poor because the increased resistance encountered by Li+ transport in and across the bulk electrolytes and the electrolyte/electrode interphases induces capacity loss and battery failures. Though tremendous efforts have been made, there is still no effective way to reduce the charge transfer resistance (Rct) which dominates low‐temperature LIBs performance. Herein, we propose a strategy of using low‐polarity‐solvent electrolytes which have weak interactions between the solvents and the Li+ to reduce Rct, achieving facile Li+ transport at sub‐zero temperatures. The exemplary electrolyte enables LiNi0.8Mn0.1Co0.1O2||graphite cells to deliver a capacity of ≈113 mAh g−1 (98 % full‐cell capacity) at 25 °C and to remain 82 % of their room‐temperature capacity at −20 °C without lithium plating at 1/3C. They also retain 84 % of their capacity at −30 °C and 78 % of their capacity at −40 °C and show stable cycling at 50 °C. [ABSTRACT FROM AUTHOR]

Abstract: Organic electrode materials are promising for green and sustainable lithium‐ion batteries. However, the high solubility of organic materials in the liquid electrolyte results in the shuttle reaction and fast capacity decay. Herein, azo compounds are firstly applied in all‐solid‐state lithium batteries (ASSLB) to suppress the dissolution challenge. Due to the high compatibility of azobenzene (AB) based compounds to Li3PS4 (LPS) solid electrolyte, the LPS solid electrolyte is used to prevent the dissolution and shuttle reaction of AB. To maintain the low interface resistance during the large volume change upon cycling, a carboxylate group is added into AB to provide 4‐(phenylazo) benzoic acid lithium salt (PBALS), which could bond with LPS solid electrolyte via the ionic bonding between oxygen in PBALS and lithium ion in LPS. The ionic bonding between the active material and solid electrolyte stabilizes the contact interface and enables the stable cycle life of PBALS in ASSLB. [ABSTRACT FROM AUTHOR]