Presodiation technology: progress, strategy and prospects of sacrificial cathode additives in sodium-based energy storage systems

Presodiation technology plays a pivotal role in enhancing the reversible cycle capacity and initial coulomb efficiency (ICE) of sodium-based energy storage systems (SESSs) by pre-supplementing active sodium ions in the electrode materials, which is crucial for the practical application of SESSs. This technology encompasses various methods, including direct contact presodiation (DC), electrochemical presodiation (EC), chemical presodiation, sodium-rich cathode materials presodiation and sacrificial cathode additive (SCA) presodiation. However, the first four methods encounter specific challenges such as safety concerns, complex procedures, high costs or low irreversible capacity, which significantly impede their industrialization progress. In contrast, the SCA method distinguishes itself with its enhanced safety, straightforward operation, low cost, and superior irreversible specific capacity. More importantly, this method demonstrates excellent compatibility with existing methods of constructing SESS, delivering significant potential for industrialization. Herein, this review summarizes the latest research advancements in SCA presodiation technology, with a particular emphasis on optimizing strategies for some close "ideal" SCA enhancement. The aim of this review is to deepen the understanding of SCA presodiation technology and to offer guidance for the commercial application of high energy density SESSs.