Diffusion-limited adaptive battery charging

A lithium-ion battery with an adaptive charging mechanism, comprising:

• a transport-limiting electrode governed by diffusion;
• an electrolyte separator;
• a non-transport-limiting electrode;
• a current sensor configured to measure a charging current for the battery;
• a voltage sensor configured to measure a voltage across terminals of the battery;
• a charging source configured to apply a charging current or a charging voltage to the battery;
• a controller configured to receive inputs from the current sensor and the voltage sensor, and configured to send a control signal to the charging source;
• wherein, while the battery is charging, the controller is configured to:
• charge the battery with a fixed current for a fixed time period,
• enter a zero current state in which the charging current is set to zero,
• during the zero current state, measure an open circuit voltage for the battery at two times while the open circuit voltage relaxes toward a steady state, and
• calculate a charging current or a charging voltage based on the measured open circuit voltages, and
• apply the charging current or the charging voltage to the battery.

A non-transitory computer-readable storage medium storing instructions that when executed by a controller for a battery cause the controller to perform a method for adaptively charging a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode governed by diffusion, an electrolyte separator and a non-transport-limiting electrode, the method comprising, while the battery is charging:

• charging the battery with a fixed current for a fixed time period;
• entering a zero current state in which the charging current is set to zero;
• during the zero current state, measuring an open circuit voltage for the battery at two times while the open circuit voltage relaxes toward a steady state;
• and
• calculating a charging current or a charging voltage based on the measured open circuit voltages;
• and
• applying the charging current or the charging voltage to the battery.

A method for adaptively charging a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode governed by diffusion, an electrolyte separator and a non-transport-limiting electrode, comprising:

• determining a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator based on a diffusion time for lithium in the transport-limiting electrode;
• calculating a charging current or a charging voltage for the battery based on the determined lithium surface concentration;
• and
• applying the charging current or the charging voltage to the battery.