Designing a Corrosion Inhibiting Layer to Enhance Cycling Stability of 4.7 V Ni‐Rich Cathode

Abstract The advent of Ni‐rich cathode promises to increase their energy density of lithium (Li) ion batteries. However, the inherent catalytic activity and resultant decomposition products deteriorate the interfacial stability of Ni‐rich cathode. This case is further exacerbated by a higher operation voltage for delivering more capacity. Here, a facile strategy is reported for coating garnet solid electrolyte as a corrosion inhibiting layer for Ni‐rich cathode, aiming to establish an efficient Li‐conducting and stable interface that reinforces the Li transport and withstands the HF attack, respectively. Benefiting from this design, the interface of modified Ni‐rich cathode exhibits less polarization and fewer side reactions even at a cut‐off voltage of 4.7 V. This difference is mainly attributed to the fast Li transport stemming from the compatibility between Ni‐rich cathode and garnet solid electrolyte. Meanwhile, the stable and dense cathode electrolyte layer, observed by cryo‐transmission electron microscopy characterization, inhibits side reaction between Ni‐rich cathode and liquid electrolyte. This work provides an effective strategy to reinforce the interfacial stability of Ni‐rich cathode and has the potential to advance the commercialization of Ni‐rich cathodes.