Drop-in electrode technology facilitates 10-minute EV charging at -10C

Current Li-ion batteries suffer from limited performance under fast-charge, low-temperature, and thick-electrode conditions, where multiple mass transport and interfacial kinetic effects must be simultaneously addressed. Consequently, design trade-offs limit the usage of batteries in applications that are challenging to electrify, particularly in extreme environments and configurations where thermal management is not feasible. Introducing a strategy that permits for extreme fast charging (up to 6C) at low temperatures (down to −10C) while maintaining technologically relevant electrode loadings >3mAh/cm2. A synergistic strategy is employed utilising surface coatings and 3D-architected graphite anodes, which can handle transport and interfacial limitations under these extreme conditions without harmful lithium plating. This study supplies fundamental insights into the dominant mechanisms that control Li plating and capacity fade under low-temperature and fast-charge conditions.

Highlights

• 6C fast charging of Li-ion batteries is demonstrated at −10°C without Li plating
• 3D electrodes and artificial SEI coatings improve transport and interface kinetics
• Three-electrode measurements decouple interface/transport effects at low temperatures
• Fast charging at low temperatures can enhance EVs in cold climates

Summary

Managing the trilemma between fast-charging, low-temperature operation, and high-energy-density electrodes is crucial to advance Li-ion batteries. Here, a strategy is introduced that integrates 3D electrode architectures with an artificial solid-electrolyte interface (SEI) employing atomic layer deposition of a solid electrolyte (Li3BO3-Li2CO3). These synergistic modifications improve mass transport and interfacial kinetics under low temperatures and fast charging, increasing the accessible capacity of thick electrodes (>3mAh/cm2). To decouple the contributions from electrolyte transport and interfacial impedance, graphite/LixNiyMnzCoaO (NMC) pouch cells were fabricated and their electrochemical performances were tested under low-temperature, fast-charging conditions. At a 6C-rate and a temperature of −10C, these integrated electrodes facilitated a >500% increase in accessible capacity and >97% capacity retention after 100 cycles, without Li plating. The capacity retention under low-temperature, fast-charging conditions also depended on the state-of-charge swing, highlighting the charging protocol's importance to minimising Li plating.