Strongly solvating triglyme-based electrolyte realizes stable lithium metal batteries at high-voltage and high-temperature

The electrolyte in lithium -metal batteries (LMBs) plays a pivotal role in stabilizing the surface of the lithium metal anode (LMA) and high -voltage cathode. However, currently widely studied ether -based electrolytes, although it has good compatibility with LMA due to their lower reactivity, are facing significant challenges related to poor oxidation resistance and cathode/electrolyte interface (CEI) instability when combined with the high -voltage cathode, particularly at elevated temperatures. Therefore, there is an urgent need to design advanced electrolytes capable of maintaining high stability under high -voltage and high -temperature conditions. Here, we have developed an ultra -stable localized high -concentration electrolyte (LHCE) by introducing triethylene glycol dimethyl ether (TG), which exhibits strong solvation ability. Computational and experimental results demonstrate that the designed TG -based dilute high -concentration electrolyte (TG-DHCE) possesses a stable solvation structure, high oxidation resistance, and thermal stability, making it ideal for LMBs. Furthermore, the unique solvation structure of TG-DHCE promotes the preferential decomposition of anions while facilitating the formation of stable, inorganic -rich electrode/electrolyte interfaces on the anode and cathode. Consequently, equipped with TG-DHCE, Li||Li cells (more than 1600 h) and Li||NCM523 cells (80.6%, 250 cycles) show superior stability and also demonstrate remarkable performance even at elevated temperatures (60 degrees C). Additionally, under the harsh conditions of ultrahigh loading NCM523 cathode (19.7 mg/cm 2 ) and limited Li reservoir (twice excess Li was deposited on Cu, Li@Cu) (N/ P = 2), Li@Cu||NCM523 cells still maintain stable operation. This work pioneers a new path by choosing strongly solvating solvents, effectively enhancing the cycle life of LMBs under high -voltage and high -temperature conditions.