Cathode coatings and electrolyte additives for CEI stabilization

Lithium-ion batteries are a vital part of the transition to renewable energies and electrified transportation. To achieve higher cell energy densities, Ni-rich layered oxides with capaci-ties above 200 mAh g-1 and average voltages above 3.7 V are of particular interest. However, high nickel contents (above 80%) make the cathode active materials (CAM) susceptible to a variety of degradation phenomena, including phase transitions from the layered to a rock-salt structure, electrolyte decomposition at the electrode interface, particle cracking with subsequent contact loss, and transition metal dissolution followed by deposition on the anode. Effective CAM surface coatings and a robust CEI are key to minimize these effects. Within the EU project INERRANT, Fraunhofer ISC and the University of Würzburg are work-ing together to design both surface coatings and electrolyte additives based on phosphorus compounds to mitigate degradation and thus to improve both the lifetime and safety of high-nickel cathodes in LIBs.

The authors acknowledge funding from the European Union's Horizon Europe research and innovation programme under Grant Agreement No. 101147457 (INERRANT), and the in-volvement in No. 101104022 (Battery 2030 CSA3). This output reflects only the authors’ view and the European Union cannot be held responsible for any use that may be made of the information contained therein.