Obviousness

Obviousness Analysis of US Patent 11799131 under 35 U.S.C. § 103

To determine the obviousness of US patent 11799131, we must consider whether the claimed invention as a whole would have been obvious to a person having ordinary skill in the art (POSA) at the time of the invention, based on combinations of prior art references. An invention is considered obvious if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains.

The present patent, US11799131, focuses on an electrolyte and an electrochemical device, particularly emphasizing an electrolyte composition comprising a dinitrile compound, a trinitrile compound, and propyl propionate, and specific electrode compaction densities. The stated purpose is to form a firm protective film on the cathode, inhibit solvent decomposition, and improve DC internal resistance and storage performance, especially at high voltages.

The patent states that its filing date is 2022-08-11, and its priority date is 2018-09-21. Therefore, prior art references with an effective filing or publication date before 2018-09-21 would be relevant for this analysis.

The prior art references explicitly listed in the US11799131 patent are:

• U.S. Pat. No. 9,812,739B

Potential Combinations and Rationale for Obviousness:

Given the information provided within the patent itself regarding prior art and the stated problems, the following combination of prior art references could render certain claims of US11799131 obvious:

Combination 1: U.S. Pat. No. 9,812,739B in view of general knowledge in the art regarding electrolyte additives.

• U.S. Pat. No. 9,812,739B as a Primary Reference: US 9,812,739B is explicitly incorporated by reference in US11799131 for anode and cathode preparation, as well as cathode active material composition. This indicates that a POSA would be familiar with the electrochemical devices and components described in US 9,812,739B. Specifically, the patent mentions using techniques from US 9,812,739B for preparing anodes and cathodes, and for the composition of lithium-transition metal compounds for cathode active materials.

• Motivation to Combine with Known Electrolyte Additives (Dinitriles, Trinitriles, Propyl Propionate): US11799131 acknowledges that dinitrile compounds are known to form protective films on cathodes to inhibit solvent decomposition. The "Background" section of US11799131 discusses the problem of electrolyte decomposition and battery material deterioration at high voltages (above 4.4V) and the need for improved electrochemical devices. While dinitrile compounds were known for protective film formation, their protective effect was considered not sustainable for long periods at high potentials.

  A POSA, facing the problem of limited protective film stability of known dinitrile compounds at high potentials (a problem recognized in the background of US11799131), would have been motivated to explore various combinations of known electrolyte additives to enhance film stability and overall battery performance. Propyl propionate is listed in US11799131 as a common chain carboxylate ester solvent, suggesting its general availability and use in electrolytes. Trinitrile compounds, as a class of compounds with multiple cyano groups, are structurally related to dinitriles and a POSA would recognize their potential for similar or enhanced film-forming properties due to the increased number of polar cyano groups.

  Therefore, a POSA, starting with the electrochemical device described in U.S. Pat. No. 9,812,739B and seeking to improve high-voltage performance and electrolyte stability, would have found it obvious to experiment with combinations of film-forming additives like dinitrile and trinitrile compounds, along with common electrolyte components like propyl propionate, to find a synergistic effect that leads to a more stable protective film. The specific ratios (X, Y, Z, X+Y, X/Y, Y/Z) and ranges claimed in US11799131 (e.g., about 2 wt % ≤ (X+Y) ≤ about 11 wt %, about 0.1 ≤ (X/Y) ≤ about 8, about 0.01 ≤ (Y/Z) ≤ about 0.3) could be considered within the realm of routine experimentation for a POSA optimizing additive concentrations for improved performance, once the general idea of combining these types of additives was conceived.

  The patent itself states: "The present inventors unexpectedly found that by using a mixture of a dinitrile compound, a trinitrile compound and propyl propionate, a firm protective film which is not easily decomposed on the surface of the cathode at a high potential can be formed." While the outcome may have been "unexpected," the initial motivation to combine these known types of compounds to address a known problem (unstable protective films at high voltage) could be considered obvious to a POSA.

This analysis is based solely on the information provided in US patent 11799131 and the nature of prior art under 35 U.S.C. § 103. A more comprehensive obviousness analysis would typically involve a detailed search and review of all relevant prior art published before the priority date.