Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of Claims
Claim 22 is cancelled. Claims 1-13 stand withdrawn. Claims 14-21, as filed 26 June 2025, are examined herein. No new matter is included herein.
Response to Arguments
Regarding the rejection under 35 USC 103, Applicant argues that Claim 14 requires that the discharging solution comprises an aqueous solution of salts sharing a common anion and having a redox couple as cations. The claim further requires disengaging the contact between the external electrodes and the discharging solution when the voltage measured by the voltage sensor across the external electrodes of the spent Li-ion battery is below a threshold voltage. In other words, the claim requires that the redox couple be present even after the voltage measured in the voltage sensor across the external electrodes is below the threshold voltage. This argument is moot in light of a newly cited reference, Zhang, which discloses the use of two cations and an organic acid (reducing agent). Therefore, when cations forming a redox couple are selected, the redox couple will be in place for the duration.
Applicant further argues (claim 22) against Examiner’s argument that Fe2+ and Fe3++ of modified Yao would come to an equilibrium based on the disclosure of Yuan or Beltran-Prieto. However, the Examiner's suggestion ignores the fact that neither Yuan nor Beltran-Prieto introduce electrons into the Fe+/Fe3+ systems disclosed therein. Applicant further argues that “to the extent that Beltran-Prieto shows an equilibrium between ferrous and ferric sulfates can be achieved, the pertinent discussion relates to oxidation of FeSO4 in air and does not account for the electrons introduced during the discharging process; nor does Beltran-Prieto provide any evidence that the equilibrium concentration would be reached within the claimed ranges.” This argument is moot in light of a newly cited reference, Zhang, which discloses the use of two cations and an organic acid (reducing agent).
Applicant further argues that because Yao discloses that 0.8 mol/L is better than 0.4 mol/L, that Yao teaches against the use of a lower concentration solution. Examiner notes that Yao’s discharge solution appears to have only one cation. The rejection provided herein replaces Yao’s FeSO4 with Zhang’s improved discharge solution of both ferrous and ferric sulfate and further comprising an organic acid. Therefore, the person of ordinary skill is motivated to optimize the ion concentration of the new discharge solution, rather than use Yao’s proposed concentration.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 14-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yao (Yao, Lin Peng, et al. "An environmentally friendly discharge technology to pretreat spent lithium-ion batteries." Journal of Cleaner Production 245 (2020): 118820) in view of Zhang (CN 114552044 A, with citations to the provided Espacenet translation) and Horie (US 20230361370 A1).
Regarding claim 14, Yao teaches (FIG. 7) a system for discharging a spent Li-ion battery.
Yao teaches (FIG. 7) a container comprising an aqueous discharging solution (page 6 col. 2 FeSO4 solution in water, FIG. 4C 0.4 mol/L and 0.8 mol/L as non-limiting examples) but Yao does not explicitly teach the solution comprising an aqueous solution of (multiple) salts and an organic acid, the salts sharing a common anion and having a redox couple as cations; wherein the redox couple comprises a first cation of a metal having a first oxidation state and a second cation of the same metal having a second oxidation state different from the first oxidation state.
Zhang discloses [0001] rapid and safe release of residual charge and [0006] a composite electrolyte solution for the safe and efficient discharge of spent lithium-ion batteries, and at [0007] discloses that the inorganic salts (first cation) are soluble in water and may be selected from options including ferric sulfate, and may include a reducing agent, where the candidates include one or more of ferrous sulfate (second cation) and ascorbic acid (an organic acid). At [0038], Example 4 provides support for selection one sulfate salt from the inorganic salt list, in combination with both ferrous sulfate and ascorbic acid from the reducing agent list.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to replace Yao’s FeSO4 solution with selections from Zhang’s list of inorganic salts and reducing agents, with a reasonable expectation of successfully having rapid and safe release of residual charge. The person of ordinary skill would have been motivated to specifically select Zhang’s ferric sulfate (first cation), ferrous sulfate (second cation), and ascorbic acid (organic acid) to make the discharge solution, as these represent a selection from a finite number of identified, predictable solutions, with a reasonable expectation of success, thus meeting the limitation the salts sharing a common anion and having a redox couple as cations; wherein the redox couple comprises a first cation of a metal having a first oxidation state and a second cation of the same metal having a second oxidation state different from the first oxidation state.
Regarding the limitation wherein the aqueous solution comprises a salt with the first cation at a concentration in a range from about 0.1 M to about 0.3 M and a salt with the second cation at a concentration in a range from about 0.1 M to about 0.15 M, Yao at page 2 column 1 contemplates the need to optimize the medium and concentration of the discharge solution, for the purpose of improved efficiency and reduced environmental impact. However, Yao discloses (FIG. 4C, a non-limiting example) ferric sulfate discharge solution at 0.4 and 0.8 mol/L, which is outside of the claimed range. Zhang at [0007] discloses the inorganic salts in a range of 0.1 to 5 M, and the reducing agent also in a range of in a range of 0.1 to 5 M, which encompasses the instant claim limitation.
The person of ordinary skill in the art would have been motivated to optimize the discharge solution of modified Yao with the first and second cation concentrations based on the ranges taught by Zhang, in order to balance efficiency and environmental impact, with a reasonable expectation of selecting a value in the overlapping part of the range.
Regarding the limitation initiate a contact between external electrodes of the spent Li-ion battery and the discharging solution, and disengage the contact between the external electrodes and the discharging solution when the voltage measured by the voltage sensor across the external electrodes of the spent Li-ion battery being below a threshold voltage, Yao further teaches (FIG. 7) a conveyor belt which initiates and disengages contact between the external electrodes and the discharge solution, however, Yao does not explicitly teach a voltage sensor configured to measure a voltage across external electrodes of the spent Li-ion battery; a controller operably connected to the voltage sensor, and configured to: initiate a contact between external electrodes of the spent Li-ion battery and the discharging solution, and disengage the contact between the external electrodes and the discharging solution when the voltage measured by the voltage sensor across the external electrodes of the spent Li-ion battery being below a threshold voltage.
Horie, in the same field of endeavor, discloses (FIG. 2 and ([0057]) a discharging device 12 comprising a control unit 32 and a voltometer 30 (voltage sensor). At FIG. 3 and ([0064-0066]), Horie discloses discharge step S102 and S104 with voltage monitoring, where the discharge process ends when a lower voltage limit is reached. At ([0075]) Horie discloses a 5th embodiment, where two discharge tanks are used to carry out the discharge process.
A person of ordinary skill in the art would have been motivated, as of before the effective filing date of the instant invention, to select the control unit and voltage sensor of Horie for use with the conveyor belt and aqueous discharging solution of modified Yao, in order to have the controller monitor voltage and control belt speed, with a reasonable expectation of successfully monitoring the discharge process for safety, and setting a belt speed in the tank such that a battery with a voltage sensor affixed will be efficiently and safely discharged.
Regarding claim 15, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Zhang discloses [0007] ferric sulfate and ferrous sulfate, which create a sulfate anion (a candidate within the scope of the claimed list of alternatives). The motivation to make this selection from Zhang, as set forth in claim 14, is incorporated herein by reference.
Regarding claim 16, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Zhang discloses at [0007] ferric sulfate and ferrous sulfate, (equivalent to Fe2+/Fe3+) which is a candidate within the scope of the claimed list of alternatives. The motivation to make this selection from Zhang, as set forth in claim 14, is incorporated herein by reference.
Regarding claim 17, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Zhang discloses at [0007] discloses an aqueous solution of ferrous sulfate and ferric sulfate. The motivation to make this selection from Zhang, as set forth in claim 14, is incorporated herein by reference.
Regarding claim 18, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Yao further teaches (FIG. 4(c)) the discharge of the batteries wherein the threshold voltage is in a range from about 0.1 V to about 1.5 V.
Regarding claim 19, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Yao further teaches (see FIG. 7) wherein initiating contact between external electrodes of the spent Li-ion battery and the discharging solution comprises immersing the spent Li-ion battery into the container such that external electrodes of the spent Li-ion battery contact the discharging solution, and disengaging the contact between the external electrodes of the spent Li-ion battery comprises removing the spent Li-ion battery from the container such that the external electrodes do not contact the discharging solution.
Regarding claim 20, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Yao teaches (FIG. 7) a conveyer belt and sediment scraper in the discharge solution tank, and the motivation for the conveyor belt to be controlled by the controller, as set forth in claim 14, is incorporated herein by reference. The instant specification at ([0048]) teaches the need for stirring to actively remove evolved gas or deposited materials, and teaches that suitable types of stirring include a magnetic stirrer, ultrasound, or a rocker mechanism. A person of ordinary skill in the art would have understood, as of before the effective filing date of the instant invention, that the conveyor belt of Yao would help to remove evolved gas or deposited materials, thus meeting the instant claim limitation (…comprising an ultrasound generator configured to generate ultrasound vibrations and apply the ultrasound vibrations to the discharging solution, wherein the controller is further configured to control the ultrasound generator.)
Regarding claim 21, Yao in view of Zhang and Horie teaches all of the limitations as set forth above. Yao page 1 column 2 mentions a Tesla Model S vehicle bursting into flames because of battery damage in a collision. However, Yao does not explicitly teach a temperature regulator operably coupled to the container and configured to maintain the temperature of the discharging solution while the external electrodes are contacted with the discharging solution. A person of ordinary skill in the art would have understood, as of before the effective filing date of the instant invention, that discharging batteries into a discharge tank will increase the temperature of the discharge liquid, and would have understood the importance of monitoring the temperature of the discharge tank, in order to avoid triggering thermal runaway in batteries being recycled, and would have therefore added a cooling system to the discharge solution tank, with a reasonable expectation of reducing the risk of thermal runaway.
Conclusion
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CLAIRE A. RUTISER
Examiner
Art Unit 1751
/C.A.R./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 11/3/2025