Cobalt-free, high-nickel cathode batteries are moving fast toward commercial scale because they can improve driving range while reducing dependence on scarce critical minerals. Among the leading designs are manganese-coated, nickel-rich systems that aim to balance performance and cost. Yet a new study warns that one overlooked manufacturing detail may quietly shorten battery lifetime.
Researchers led by Professor Jin Ho Bang at Hanyang University, with PhD scholar JinHa Shim, show that exposing manganese-containing precursor materials to air during storage can trigger subtle but consequential chemistry. The work links this preprocessing step to later electrochemical instability during cycling, offering a practical path to more durable cathodes.
The key culprit is manganese. In these nickel-rich electrodes, manganese is used to stabilize the layered structure, but air exposure oxidizes manganese at particle surfaces. That oxidation drives the formation of defective regions populated by Jahn–Teller distorted manganese species—an arrangement that is more reactive than the intended, well-bonded surface chemistry.
Once cycling begins, those reactive defective surfaces accelerate electrolyte decomposition and promote transition-metal dissolution. The released metals then participate in damaging reactions at the graphite anode interface, undermining the stability of the full cell. In nickel-rich systems, the defect pathway can nearly double the rate of capacity fading over long-term tests.
The findings emphasize that the manganese-rich shell—typically added to protect the cathode—can become a catalyst for degradation if precursor history is not controlled. “Even small variations in precursor storage history can substantially affect battery stability,” the team notes, underscoring the sensitivity of electrode performance to upstream processing.
To counter the problem, the researchers introduce a simple manufacturing adjustment: increasing excess lithium during synthesis. This change suppresses formation of the defective surface phase and restores more stable manganese–oxygen bonding.
Cathodes prepared with the modified lithium stoichiometry retained over 90% of their capacity in durability-focused cycling, demonstrating a measurable performance recovery without requiring expensive redesigns of the production line. The approach translates directly into stronger quality control requirements for large-scale manufacturing.
Overall, the study reframes “cobalt-free” progress as incomplete without a deeper understanding of how manganese chemistry evolves from precursor storage to final electrode structure. Managing precursor exposure and lithium stoichiometry could help batteries last longer in electric vehicles and large-scale energy storage.
Keywords
Cobalt-free cathodes, manganese chemistry, precursor oxidation, Jahn–Teller distortion, electrolyte decomposition, transition-metal dissolution, lithium stoichiometry, electric vehicle batteries
Subject of Research: Not provided
Article Title: Precursor-driven Jahn–Teller distortion as a hidden origin of surface instability in Mn-stabilized Ni-rich cathodes
News Publication Date: 13-May-2026
Web References: https://doi.org/10.1039/d6ee00713a
References: 10.1039/d6ee00713a
Image Credits: Credit: Professor Jin Ho Bang from Hanyang University
