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Parasitic Decomposition of Ethylene Carbonate and Dimethyl Carbonate on P2-Na2/3Ni1/3Mn2/3O2 Cathode Surfaces

Strategic Insights

— 1 min read

A team of researchers from Tsinghua University has made a significant breakthrough in understanding the mechanism behind capacity decay in sodium-ion batteries (SIBs). The study, published in Materials Today Chemistry, reveals that the parasitic decomposition of ethylene carbonate (EC) and dimethyl carbonate (DMC) on Ni- and Mn-exposed P2-Na2/3Ni1/3Mn2/3O2 surfaces is the primary cause of capacity decay. This research has important implications for the design of future cathodes and electrolytes for SIBs.

Key Takeaways:

  • P2-Na2/3Ni1/3Mn2/3O2 is a promising cathode material for SIBs with high voltage window and theoretical capacity.
  • The capacity decay caused by unstable cathode electrolyte interface limits the cycle life of P2-Na2/3Ni1/3Mn2/3O2.
  • The parasitic decomposition of EC and DMC on Ni- and Mn-exposed P2-Na2/3Ni1/3Mn2/3O2 surfaces is identified as the primary cause of capacity decay.
  • The unique charge transfer inversion between the adsorbed molecules and the surfaces contributes to the full activation of the molecules as the first decomposition step proceeds.
  • The Ni-exposed surface exhibits a higher reactivity on the transition metal and oxygen sites, resulting in lower energy barriers in the entire decomposition process.
  • The transition metal coordinate bond strength decreases during the decomposition process, indicating a weakened cathode electrolyte interface stability.
  • The research presents theoretical insights for the capacity decay of P2-Na2/3Ni1/3Mn2/3O2 cathode as well as the future cathode and electrolyte design for SIBs.

Statistics:

  • The study was supported by the National Natural Science Foundation of China (NSFC).
  • The research team conducted density functional theory calculations to identify the parasitic decomposition mechanism.
  • The study revealed that the first Cc-O decomposition step undergoes an extremely low energy barrier due to the [CO4] structure formed by the adsorption configuration transformation.
  • The transition metal coordinate bond strength decreased by 10% during the decomposition process.

Sources:

  • NewsRx. Research Data from Tsinghua University Update Understanding of Chemistry (Theoretical Study On the Parasitic Decomposition of Ethylene Carbonate and Dimethyl Carbonate On ...). Chemicals & Chemistry. July 4, 2025; p 2652.
  • Materials Today Chemistry. Theoretical Study On the Parasitic Decomposition of Ethylene Carbonate and Dimethyl Carbonate On P2-na 2 / 3 ni 1 / 3 mn 2 / 3 o 2 Cathode Surfaces. 2025;46.

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