Specific Electrolyte for Sodium-Ion Battery {Na2/3Ni1/3Mn2/3O2 (NNMO) + Hard Carbon}, 200 g/bottle, CSIBSENMOHC

For a P2-type Na2/3Ni1/3Mn2/3O2 (NNMO) cathode paired with a Hard Carbon (HC) negative electrode, the electrolyte must manage a more severe set of chemical and phase degradation pathways than O3-type layered oxides (such as NFM111): (1) High-Voltage P2–O2 Phase Transition & Lattice Shrinkage: When charged above ~ 4.15–4.20 V vs. Na/Na+, NNMO undergoes a major, irreversible P2-to-O2 phase transformation marked by a sharp volume collapse along the c-axis (~ 23%). This lattice shearing induces intergranular micro-cracks, exposing fresh catalytic Ni^{3+/4+} and Mn^{3+/4+} sites that oxidize non-aqueous solvents. (2) Mn^{3+} Disproportionation & Jahn-Teller Dissolution: Deep sodiation and high-voltage charging trigger localized Mn^{3+} formation. Solubilized Mn^{2+} ions cross the separator and deposit onto the hard carbon anode, replacing Na+ and catalytically breaking down the Solid Electrolyte Interphase (SEI). (3) Severe Cell Gassing & Low Anode Potential: Hard carbon sodiation occurs down to ~ 0.01 V vs. Na/Na+. Catalyzed by migrated transition metals, linear carbonates and cyclic additives (like excess FEC) rapidly decompose into gaseous products (CO2, CO, fluoro-organics), leading to rapid pouch cell swelling.

Notes: Please store the specific SIB electrolyte in the glovebox due to its sensitivity to humidity.

References: 

1. C. Chen, et al. Effects of ester-based electrolyte composition and salt concentration on the Na-storage stability of hard carbon anodes, Journal of Power Sources, 2020, 471, 228455
2. A. Zeng, et al. Robust interface for O3-type layered cathode towards stable ether-based sodium-ion full batteries, Energy Storage Materials, 2025, 74, 103894