In Situ Li-Plating Diagnosis for Fast-Charging Li-Ion Batteries Enabled by Relaxation-Time Detection.

The Li-plating behavior of Li-ion batteries under fast-charging conditions is elusive due to a lack of reliable indicators of the Li-plating onset. In this work, the relaxation time constant of the charge-transfer process (τ ) is proposed to be promising for the determination of Li-plating onset. A novel pulse/relaxation test method enables rapid access to the τ of the graphite anode during battery operation, applicable to both half and full batteries.

Ethylene-Carbonate-Free Electrolytes for Rechargeable Li-Ion Pouch Cells at Sub-Freezing Temperatures.

Sub-freezing temperature presents a significant challenge to the survival of current Li-ion batteries (LIBs) as it leads to low capacity retention and poor cell rechargeability. The electrolyte in commercial LIBs relies too heavily on ethylene carbonate (EC) to produce a stable solid electrolyte interphase (SEI) on graphite (Gr) anodes, but its high melting point (36.4 °C) severely restricts ion transport below 0 °C, causing energy loss and Li plating.