Comparative Analysis of Metal Preloading Technologies in Batteries and Capacitors

Abstract

Lithium-ion batteries (LIBs) are widely used in many fields due to their high energy density and reliability. In addition, other metal-ion energy storage devices, such as those using Na⁺, K⁺, Mg²⁺, and Al³⁺ ions, offer significant technological opportunities. The emerging metal-ion batteries are attracting attention due to their abundant terrestrial reserves and potential low cost of raw materials. Preloading of lithium and other metals in the electrodes has been demonstrated as an effective strategy for enhancing battery performance. In this paper, the advances in the metal preloading technology of LIBs and emerging metal-ion batteries have been reviewed. The differences between preloading of lithium and other metals have been compared, and their mechanisms in improving the initial coulombic efficiency, cyclic stability, and overall battery performance are discussed. The basic principles and applications of lithium preloading technology are first introduced and then preloading methods in post-lithium batteries are discussed in detail, including their chemical and physical methods and their effects on battery performance. Additionally, the advantages and challenges of pretreatment technologies in various battery systems have been examined, and their potential limitations have been discussed. Finally, the future direction of lithium and other metal preloading, including the development of new materials, innovation in pretreatment methods, and the potential of these technologies in sustainable energy storage, has been discussed. Sacrificial metal-salt preloading in the cathode appears to be the most advantageous, leveraging its high energy gain, low process complexity, and superior cycling stability to achieve large-scale deployment in high-energy-density traction batteries.