Performance Evaluation and Analysis of ARC-S37 Sulfonate Derivative Electrolyte Additive

Compared with the traditional additive DTD, the core competitiveness of ARC-S37 developed by Rolechem is reflected in: superior interfacial film formation, stronger high-rate performance, better extreme-temperature adaptability, and high performance adjustability, making it more adaptable to flexible scenario deployment.

The experiment uses 1Ah pouch cells,NCM811/SiC system, 2.75V-4.25V Electrolyte scheme (common components):EC+EMC+DEC; 1.1M LiPF6; FEC, VC, PS "1.0% DTD" was set as the base control group, and "0.2% ARC-S37, 0.5% ARC-S37, 0.8% ARC-S37, 1.0% ARC-S37" were set as the experimental groups, specifically as follows: Base group: Common components + 1% DTD Experimental group A: Common components + 0.2% ARC-S37 Experimental group B: Common components + 0.5% ARC-S37 Experimental group C: Common components + 0.8% ARC-S37 Experimental group D: Common components + 1.0% ARC-S37

According to dQ/dV analysis, ARC-S37 has two film-forming potential peaks (2.1V, 2.36V), while the film-forming potential of DTD is 2.32V. Its key advantage lies in that the 2.1V film-forming potential of ARC-S37 is earlier than the 2.32V of DTD, which can achieve "preferential film formation" and inhibit further solvent consumption.

With the increase of ARC-S37 addition amount, the 2.1V film-forming peak intensity gradually becomes stronger, indicating that the film-forming reaction is more thorough and the construction of the SEI film is more complete at higher addition amounts.

The differences in initial efficiency among all groups are small. The mean initial efficiency of the base group is 79.5%, and the mean initial efficiency of the experimental groups is between 79.1% and 79.6%, among which 0.2% ARC-S37 has the highest initial efficiency (79.6%). This result shows that the preferential film-forming process of ARC-S37 does not significantly increase charge consumption, avoiding the problem of "decreased initial efficiency caused by premature film formation."

Rate performance directly reflects the practicality of the cell in high-current charge-discharge scenarios. ARC-S37 shows significant advantages in this dimension, and there is a clear addition-amount-dependent pattern:

All addition amounts of ARC-S37 are superior to the base group, and the capacity retention rate of high-rate charging has a positive correlation with the addition amount. Specifically, 1.0% ARC-S37 has the optimal performance. For example, under high-rate 4C conditions, the retention rate of DTD is significantly lower, while the retention rate of 1.0% ARC-S37 is the highest, reflecting that the SEI film constructed by this additive has better ionic conductivity.

No difference at low rates, significant advantages of ARC-S37 at high rates—≤3C rate conditions, the discharge retention rates between DTD and each ARC-S37 group have little difference; under 5C high-rate discharge conditions, all ARC-S37 groups are superior to DTD, and the more the addition amount, the more excellent the discharge performance (for example, at 5C rate discharge, the retention rate of 1.0% ARC-S37 is about 10% higher than that of DTD).

The differences among groups are extremely small, and ARC-S37 has no obvious advantage in discharge performance;

Different addition amounts of ARC-S37 are all superior to the base group, and the lower the temperature, the more obvious the advantage. For example, at -20°C, the capacity retention rate of 0.8% ARC-S37 is about 51.4%, while the base group is only 36.6%.

ARC-S37 presents a "high addition amount is optimal" feature in this dimension: 0.8% and 1.0% ARC-S37 capacity retention and recovery rates perform best, which are 2~3% higher than the base group, and their internal resistance change rates are more stable relative to the base group, indicating that the SEI film constructed by high addition amounts of ARC-S37 is not easily decomposed at high temperatures, and can effectively inhibit electrolyte oxidation and active material loss.

High-temperature cycling performance (45°C): Unlike high-temperature storage performance, 0.2% ARC-S37 performs best—its cycling capacity retention rate (300 cycles) is 1.0% higher than other groups (including DTD and high addition amount ARC-S37), while 0.5%, 0.8%, and 1.0% ARC-S37 have basically no difference from DTD. It is speculated that the SEI film constructed by low addition amount ARC-S37 is thinner and has better toughness, and is not easy to crack during long-term cycling, while an excessively thick SEI film at high addition amounts easily leads to an increase in impedance in the later stage of cycling.

Compared with the traditional additive DTD, the core competitiveness of ARC-S37 is reflected in the following 4 points: ① Better interfacial film formation: 2.1V preferential film formation, inhibiting solvent consumption, and no loss in initial efficiency; ② Stronger high-rate performance: 4C fast charge and 5C fast discharge performances are superior to DTD, adapting to high-power scenarios; ③ Better extreme temperature adaptability: -20°C low-temperature discharge retention rate is more than 15% higher than the base group, and 60°C high-temperature storage stability is 2%-3% higher than the base group; ④ Strong performance adjustability: Different addition amounts can target and optimize scenarios such as high-temperature cycling (0.2% ARC-S37), low-temperature discharge (0.8% ARC-S37), and high-rate charge-discharge (1.0% ARC-S37).

For different application scenarios, the recommended optimal addition amount of ARC-S37 is: ①arget Scenario: High-rate fast charging Recommended Addition Amount (ARC-S37): 1.00% Core Basis: Optimal high-rate charging performance, highest 4C retention rate, and good high-temperature storage stability ②Target Scenario: Low-temperature environment application Recommended Addition Amount (ARC-S37): 0.80% Core Basis: Optimal -10℃/-20℃ discharge performance, balancing high-temperature storage and rate performance ③Target Scenario: Long-cycle high-temperature scenario Recommended Addition Amount (ARC-S37): 0.20% Core Basis: Highest 45℃ cycling retention rate, and lower cost (less addition amount) ④Target Scenario: Comprehensive performance balanced demand Recommended Addition Amount (ARC-S37): 0.80% Core Basis: Low-temperature discharge, high-temperature storage, and rate performance are all at an excellent level with no obvious shortcomings In summary, the ARC-S37 electrolyte additive is superior to traditional DTD in interfacial stability, extreme temperature performance, and high-rate adaptability, and the addition amount can be flexibly adjusted according to the scenario.