This review examines the key process of lithium-ion battery cell formation. Influencing factors, challenges, experimental and simulation tools required for knowledge-based process design of current and emerging battery technologies are addressed.

The formation of lithium‐ion batteries is a time‐consuming and important process during manufacturing. During the formation, surface layers on the electrodes are formed that affect the cell performance. State‐of‐the‐art formation procedures consist of several slow current cycles as it is believed to guarantee good surface layer properties while preventing degradation processes. Herein, five different formation strategies with process times between 52.79 and 1.68 h for coin cells with a lithium reference electrode are assessed. The fastest method is based on a fast charging approach that prevents lithium‐plating. Based on a real‐time negative electrode voltage control to a threshold of 20 mV, lithium‐plating is successfully prevented while ensuring a fast formation process. The formation is finished after just one cycle and results to similar cell and electrode resistance, impedance, and capacity retention compared to the other strategies. The fast charging formation approach leads to the lowest degradation when storing the cells at 80% state of charge and 60 °C for 28 days. The results conclude that the fast charging formation method with real‐time control of the negative electrode voltage is a beneficial method as it leads to faster process times while ensuring durable cell properties.

Fast charging of lithium-ion batteries is often related to accelerated cell degradation due to lithium-plating on the negative electrode. In this contribution, an advanced electrode equivalent circuit model is used in order to simulate fast-charging strategies without lithium-plating. A novel parameterization approach based on 3-electrode cell measurements is developed, which enables precise simulation fidelity. An optimized fast-charging strategy without evoking lithium-plating was simulated that lasted about 29 min for a 0–80% state of charge. This variable current strategy was compared in experiments to a conventional constant-current–constant-voltage fast-charging strategy that lasted 20 min. The experiments showed that the optimized strategy prevented lithium-plating and led to a 2% capacity fade every 100 fast-charging cycles. In contrast, the conventional strategy led to lithium-plating, about 20% capacity fade after 100 fast-charging cycles and the fast-charging duration extended from 20 min to over 30 min due to increased cell resistances. The duration of the optimized fast charging was constant at 29 min, even after 300 cycles. The developed methods are suitable to be applied for any given lithium-ion battery configuration in order to determine the maximum fast-charging capability while ensuring safe and durable cycling conditions.