Performance Evaluation and Analysis Report of ARC-S39 New Electrolyte Solvent

ARC-S39, developed by Rolechem, is a high-performance new electrolyte solvent designed for high-voltage applications. It aims to improve the instability of electrolytes under high voltage and enhance specific cell performance. ARC-S39 replaces DEC, a conventional chain carbonate whose core functions are to reduce electrolyte viscosity and improve ion migration efficiency, but which suffers from mediocre thermal stability and limited interfacial compatibility. Therefore, the core positioning of ARC-S39 is a high-performance linear carbonate substitute solvent. This evaluation aims to verify whether it can achieve a comprehensive upgrade in overall electrolyte performance while retaining the viscosity-reducing advantages of DEC.

The experiment uses 1Ah pouch cells,LCO/Silicon-Carbon system, 3.0V-4.53V Electrolyte scheme: Base group: EC:PC:DEC:PP = 2:3:5:10; 1.1M LiPF6; DFOB, FEC, DFEC, HTCN Experimental group: EC:PC:DEC:ARC-S39:PP = 2:3:2:3:10; 1.1M LiPF6; DFOB, FEC, DFEC, HTCN

Core data: The initial discharge capacity of ARC-S39 is higher than that of the base group, with an initial efficiency of 86.69%, an increase of 1.00% compared to the base group (85.69%). The dQ/dV curves show no abnormal redox peaks under normal operating voltage conditions, further verifying that there are no adverse side reactions among the solvent, electrodes, lithium salts, and additives, indicating excellent formulation system stability.

Core data: The -10℃ low-temperature discharge performance is improved by 6.9% compared to the base group, and the 0℃ discharge performance also shows a slight advantage. The discharge performance at 10℃/25℃/55℃ is basically comparable to the base group.

Core data: There is no significant difference from the base group at low rates （0.33C/0.5C/1C）, while excellent performance is exhibited at high rates. The 4C fast charge is improved by 2.4% and the 5C fast discharge is improved by 3.0% compared to the base group.

High temperature is the "touchstone" of electrolyte performance. This evaluation verified the thermal stability of ARC-S39 from two dimensions: 60℃&14d high-temperature storage and 45℃ long-term cycling, both achieving comprehensive superiority over the base group.

Core data: The capacity retention rate and recovery rate of ARC-S39 are both higher than those of the base group; the internal resistance before storage is lower, and the proportion of internal resistance increase (%) after storage is significantly smaller than that of the base group.

Core data: Over 300 full cycles, the capacity retention rates of ARC-S39 are all higher than those of the base group, with the final retention rate improved by 2.5% compared to the base group. Furthermore, the capacity decay curve is smoother without sudden drops.

As a substitute solvent, it achieves comprehensive improvements in interfacial compatibility, thermal stability, and low-temperature performance, breaking through the technical bottleneck of traditional linear carbonates where "viscosity reduction must sacrifice stability."

It integrates into traditional electrolyte formulations in the form of "replacing 3 parts of DEC," without requiring drastic adjustments to the proportions of lithium salts and additives, showing strong adaptability to existing electrolyte formulation systems.

Synchronously carry out gradient addition amount tests for ARC-S39 to lock in the optimal performance addition range and achieve balanced optimization of overall performance.

ARC-S39 developed by Rolechem is a high-performance new electrolyte solvent that achieves a comprehensive surpass in basic electrochemical performance, extreme condition performance, and high-temperature storage and cycling performance. It corely solves the pain points of traditional DEC-based electrolytes, such as poor low-temperature performance, insufficient high-rate characteristics, and mediocre high-temperature stability. Moreover, it features strong formulation adaptability and low industrialization retrofit costs, possessing significant technical advantages and market value. The laboratory small-cell evaluation data herein fully demonstrates its technical feasibility. If subsequent stages such as large-cell verification and safety performance testing achieve equivalent levels, ARC-S39 will become a premium choice for electrolyte upgrades, particularly suitable for power battery and energy storage battery scenarios with high requirements for extreme working condition performance, providing core electrolyte technical support for new energy market expansion.