Utilizing in situ alloying reaction to achieve the self-healing, high energy density and cost-effective Li||Sb liquid metal battery

As expected, a desired electrochemical energy storage system can simultaneously combine the low-cost raw materials with ultra-high energy density and no performance degradation characteristics. Here, we use liquid lithium as the anode, solid antimony as the cathode, molten LiF–LiCl–LiBr (or molten LiF–LiCl) as the electrolyte and test the battery at 550 °C. It can provide the energy density as high as 421.6 Wh kg −1 , while the energy storage cost is only 42.4 $ kWh −1 . More importantly, due to the self-healing characteristic of the pure antimony electrode, no capacity fading is observed during 470 cycles. Therefore, with all the merits, the Li||Sb liquid metal battery has become a competitive choice in the field of grid-level energy storage. • Utilizing in-situ alloying reaction to achieve the self-healing process. • Li.||Sb liquid metal battery delivers a very high energy density of 421.6 Wh kg −1 . • The energy storage cost is the lowest among all liquid metal batteries. • The all-liquid state can also appear in the middle state of discharge.