As lithium-ion batteries become the ‘go-to’ electrical energy storage systems for everything from grid energy to consumer electronics and electric vehicles (EVs), manufacturers continue their efforts to develop batteries with longer cycle lifetimes and higher charging rates to meet the demands of a growing number of applications.
Lithium ion (Li-ion) battery manufacturers continue to develop processes to enhance electrochemical performance, especially cycle life, that plays a vital role in advancing the EV battery strategy roadmap. Various high-specific-capacity anode materials, such as silicon-based (Si) materials, tin-based materials, and transition metal oxides, are under investigation to replace current low-specific capacity graphite-based anode materials. Among these, Si material is one of the most promising candidates for next-generation anodes, due to high theoretical capacity.
However due to large volume changes of Si during the charge/discharge process, continuous destruction and reconstruction of the solid electrolyte interphase (SEI) layer, collapse of the electrode structure, and electrical contact loss of the active material, Si anodes usually suffer from poor cycling performance, seriously hindering their practical application.
Prelithiation methods may compensate for the large initial irreversible capacity of anodes. However, such a strategy still cannot improve cycling stability and irreversible Li consumption during cycling.
StoreDot’s invention describes systems and methods for regulating the level of metal ions in lithium-ion batteries that serve as a source of lithium to lithiate the battery's anode or cathode during operation, based on the battery's state of health (SoH).
StoreDot’s invention describes efficient and economical methods and mechanisms for in-situ lithiating electrodes (anodes and/or cathodes) of Li-ion battery cells. In particular, the innovation allows to compensate for the initial irreversible capacity of SEI formation.
This is achieved by electrochemically controlling the interaction between the electrodes of the battery and metal ion sources located in pouches within the battery. The metal ion sources can be optimized in terms of their position and shape to ensure uniform movement of metal ions to the electrode surfaces thereby promoting uniformity and degree of in-situ lithiation.
The invention also covers systems with a Li-ion battery cell stack, a Li source within the pouch cover, and electric circuitry for lithiating the cathodes of the battery during operation, controlled by the battery's SoH.
The described methods and mechanisms aim to improve the performance and cyclelife of Li-ion batteries by effectively lithiating the electrodes and compensating for lithium loss during battery operation.
Lithiation of both the anodes and cathodes provides flexibility and can be adjusted based on feedback from the battery management system (BMS) to optimize battery performance and stability. The lithiation process is simpler and faster for cathodes, and it can be carried out in a more spatially homogeneous manner, making it safer and more controllable compared to anode lithiation, reducing the risk of lithium metallization.
These innovative methods and mechanisms aim to improve the performance and cyclelife of Li-ion batteries by effectively lithiating the electrodes and compensating for lithium loss during operation using the battery’s SoH.
Thus StoreDot’s patented invention not only improves performance of high capacity anodes but also provides flexibility in battery design and optimization. The amount of lithium introduced can be adjusted based on the battery's SoH parameters and feedback from the battery management system. This allows for customization and fine-tuning of the lithiation process to maximize battery performance, stability, and cycling lifetime.