High-nickel LiNi0.83Co0.12Mn0.05O2 (NCM83) cathodes suffer from interfacial instability resulting from cathode–electrolyte reactions and anisotropic mechanical strain within secondary particles. Herein, we present a mechanically adaptive cathode–electrolyte interphase (CEI) engineered via a dynamic covalent network that features a supramolecular ion-conducting polyurethane ureido-pyrimidinone (SPU-UPy) elastomer. The dynamic network integrates cooperative hydrogen bonds and disulfide bonds and imparts exceptional mechanical resilience and autonomous self-healing capabilities that allow it to accommodate volume fluctuations without compromising structural integrity. The SPU-UPy layer is also designed with strong transition metal ion–O/N coordination bonds that greatly enhance adhesion to the NCM83 surface and mitigate transition metal dissolution in the electrolyte. The polyether backbone facilitates efficient Li-ion transport across the interface and ensures a homogeneous interfacial Li concentration during intercalation/deintercalation. Consequently, the dynamic CEI-coated NCM83 cathodes achieve exceptional long-term cycling stability with a high-capacity retention of 82.2% after 400 cycles at 1 C. This work elucidates the critical role of dynamic covalent chemistry in stabilizing Ni-rich cathode interfaces and establishes a new paradigm for the design of high-energy-density batteries through mechano-adaptive interfacial engineering.
Li et al. (2025) studied this question.