Indigenous Energy Storage Technologies Pvt. Ltd. v. Deputy Controller of Patent and Designs & Anr.

High Court of Delhi | 12 March 2026, Case Number: C.A. (COMM.IPD-PAT) 3/2025 & I.A. 3472/2025 Bench: Hon’ble Ms. Justice Jyoti Singh

BACKGROUND

The appellant, Indigenous Energy Storage Technologies Pvt. Ltd., is a company specialising in sustainable energy storage solutions, particularly sodium-ion battery technology, with a focus on transforming agricultural and bio-waste such as cattle manure and sodium precursors into economically viable and environmentally friendly battery components. The first respondent is the Deputy Controller of Patents and Designs. The second respondent is the post-grant opponent whose identity is not further specified in the uploaded judgment.

The subject patent is Indian Patent No. 373806 (IN’806), titled “Cattle Manure Derived Hard Carbon as Electrode Material for Sodium Ion Batteries and Super Capacitors.” The patent application was filed on 04.11.2020 and the appellant requested examination on 17.11.2020. After publication on 27.11.2020, the First Examination Report was issued on 06.01.2021 and the response was filed by the appellant on 15.06.2021. The patent was granted on 04.08.2021.

The invention relates to a unique and scalable process to produce hard carbon from cattle manure for use in sodium-ion batteries and supercapacitors. The key benefits of the invention as averred by the appellant include cost-effectiveness, environmental sustainabilityand superior technical performance. The object of the invention is to provide a facile, cost-effectiveand industrially scalable method for producing cattle manure-derived hard carbon as a potential electrode material for sodium-ion batteries and supercapacitors; to provide an environmentally safe method for preparation of electrode material; and to prepare a low-cost electrode material from biological waste.

The granted claims of IN’806 cover four claims. Claim 1 is a process claim comprising the steps of: (A) drying the biomass precursor at a temperature in the range of 50°C to 100°C; (B) grinding the product received after step A; (C) mixing the obtained material with an acid solution specifically hydrofluoric acid (HF), phosphoric acid (H3PO4) or hydrochloric acid (HCl) having molar concentration between 0.1 M to 5.0 M, for 1 hour to 48 hours, at a temperature between 25°C to 60°C; (D) washing the material with de-ionised water; (E) drying the washed material at low pressure of 10-2 to 10-3 torr at a temperature between 60°C to 100°C; and (F) high temperature calcination of the dried material involving single or multi-step controlled environment in nitrogen or argon gas and heating and cooling processes in the range of 700°C to 1600°C for 0.5 hours to 12 hours. Claim 2 is a dependent claim specifying that the biomass precursor from cattle manure is selected from cow manure, bull manure, male or female buffalo manure, male or female goat manure, male or female sheep manure or poultry manure. Claim 3 is a product-by-process claim covering the carbonaceous electrode material for rechargeable metal-ion batteries prepared by the method as claimed in Claim 1, where the rechargeable metal-ion battery is selected from lithium-ion, sodium-ion, potassium-ion, magnesium-ion or calcium-ion batteries. Claim 4 is a dependent product-by-process claim specifying a composite electrode for sodium-ion batteries consisting of synthesised hard carbon material, binderand carbon black in mass percentages of (80±x): (10±y): (10±z) respectively, where x, yand z vary between 0 to 20 such that the proportional percentage sum remains one hundred.

A post-grant opposition was filed by Respondent No. 2 on 03.08.2021 one day before the patent was formally granted under Section 25(2)(b), (e)and (g) of the Patents Act, 1970. The opponent relied upon three prior art documents: D1, being WO 2020/208341 published on 15.10.2020; D2, being the textbook “Atkins’ Physical Chemistry”, Eighth Edition (2006) by Peter Atkins and Julio De Paula; and D3, being US 2002/0192553 published on 19.12.2002. The appellant filed a reply to the opposition on 30.09.2022. After hearing and filing of written submissions, Respondent No. 1 passed the impugned order on 18.10.2024 revoking IN’806 under Section 25(2)(e) for lack of inventive step and under Section 25(2)(g) for insufficient disclosure. The opposition under Section 25(2)(b) for lack of novelty was rejected by Respondent No. 1 as non-sustainable.

The reasoning of Respondent No. 1 on the lack of inventive step ground, in summary, was that: D1 implicitly discloses the drying step since animal-derived waste material is typically transported in dry or semi-dry form; the difference in material being subjected to pre-treatment with HF acid solution cannot be considered an inventive step since D1 also discloses use of HF solution to decrease concentration of SiO2 and other metallic impurities; mere change in the range of molar concentration of HF solution and mixing time is not an inventive step; selection of drying parameters such as duration, temperature and pressure cannot be an inventive step in view of D1 and D2 combined; D1 discloses that the charring step can be omitted for hard carbon electrode material with high purity and low pyrolysis yield; and in view of D1 and D3 combined, Claim 4 does not involve an inventive step. On the insufficient disclosure ground, Respondent No. 1 found that the scope of Claims 2 and 3 was broader than the detailed description which spoke only of cow manure and sodium-ion batteries respectively; that Claims 3 and 4, being product-by-process claims, were ambiguous in nature; that the patentee had not provided experimental data regarding pyrolysis yield or higher yield from the claimed process despite being asked to do so; and that it was therefore unclear whether the claimed process was industrially scalable.

The appellant filed the present appeal under Section 117A of the Patents Act, 1970 for quashing the impugned order. The appellant also filed a separate application before this Court seeking to place on record additional evidence comprising Document-L (an expert opinion reaffirming the distinction between the subject patent and prior references D1, D2and D3), Document-M (data showcasing superior yield of the claimed invention)and Document-N (a letter dated 08.11.2024 intimating about the impugned order). This application was allowed at the outset by the Court in light of Union of India v. Ibrahim Uddin and Another, (2012) 8 SCC 148, on the ground that the documents had a bearing on just adjudication of the appeal as also on the post-grant opposition.

ISSUES FOR DETERMINATION

Whether Respondent No. 1, while determining lack of inventive step under Section 25(2)(e), had followed the mandatory five-step test laid down by the Division Bench of this Court in F. Hoffmann-La Roche Ltd. & Anr. v. Cipla Ltd., 2015 SCC OnLine Del 13619 specifically whether Respondent No. 1 had identified the person skilled in the art, identified the inventive concept embodied in the patent, identified the differences between the prior art and the claimed inventionand determined whether those differences would have been obvious to a person skilled in the art without resort to hindsight and if not, whether the failure to follow this mandatory five-step analysis was sufficient to vitiate the impugned order.
Whether the inventive step objection was correctly sustained, having regard to the specific differences between the claimed process in IN’806 and the processes disclosed in prior arts D1, D2and D3, including in particular: the absence of pre-treatment steps such as sink and float treatment in the claimed invention; the absence of the charring or carbonisation step in the claimed invention which is an essential step in D1; the difference between the use of HF at 25°C to 60°C in the claimed invention and the use of HCl at 80°C to 120°C in D1; the characterisation of D2 as a non-analogous prior art; and the permissibility of mosaicking D1, D2and D3 without a demonstrated motivation for a skilled person to combine them.
Whether the ground of insufficient disclosure under Section 25(2)(g) was correctly sustained, having regard to the appellant’s contention that: the sufficiency requirement is met if at least one way of working the invention is clearly described so as to enable a skilled person to carry out the invention; the records did not substantiate the impugned order’s observation that the appellant had been given an opportunity to furnish experimental data and had failed to do so; and the scope of Claims 2 and 3 was not rendered insufficient merely because the detailed description was more limited in scope than the claims.
Whether given the infirmities identified in the impugned order, the appropriate remedy was to set aside the order and decide the matter on the merits of the appeal or to remand the matter to Respondent No. 1 for fresh consideration, taking into account the additional evidence allowed by this Court and all submissions already on record.

KEY HOLDINGS OF THE COURT

On the failure to follow the mandatory five-step test for inventive step, the Court held that Respondent No. 1 did not follow the first step of identifying an ordinary person skilled in the artand that this failure vitiated the impugned order. The Court relied on the Division Bench judgment in F. Hoffmann-La Roche Ltd. & Anr. v. Cipla Ltd., 2015 SCC OnLine Del 13619, which laid down the five steps to be followed sequentially in evaluating obviousness and inventive step. It further relied on Tapas Chatterjee v. Assistant Controller of Patents and Designs and Another, 2025 SCC OnLine Del 6369, in which another Division Bench of this Court confirmed that the five steps in F. Hoffmann must be followed sequentially while examining the aspect of obviousness and inventive step. It also relied on Agriboard International LLC v. Deputy Controller of Patents and Designs, 2022 SCC OnLine Del 940, in which this Court had held that while rejecting an application for lack of inventive step, discussion on prior art, the subject inventionand the manner in which the subject invention would be obvious to a person skilled in the art is mandatoryand that merely arriving at a conclusion that the subject invention lacks inventive step would be contrary to Section 2(1)(ja) of the Patents Act, 1970.
The Court found that Respondent No. 1 had also not followed the fifth step of the F. Hoffmann test namely deciding whether the identified differences, viewed in the knowledge of the alleged invention, would have been obvious to the ordinary person skilled in the art, while ruling out a hindsight approach. The Court found that the impugned order had applied a hindsight approach and had not considered in the right perspective the significant differences flagged by the appellant between the claimed process and D1, particularly: the pre-treatment steps involving sink and float treatment in D1 which are absent in the subject patent; the charring step being an essential and mandatory step in D1 which is entirely absent in the subject patent; the material being subjected to acid treatment in D1 being different from the material treated in the instant patent since D1 treats charred material with HCl at 80°C to 120°C whereas the instant patent treats uncharged material with HF at 25°C to 60°C; and the important distinction that HF in the claimed invention dissolves and removes SiO2 and metallic impurities whereas HCl in D1 fails to eliminate silica, such that the instant invention yields technically advanced purity and industrial superiority.
On the characterisation of D2 and D3 as non-analogous prior art and the impermissibility of their mosaicking with D1, the Court found that Respondent No. 1 had not considered the Appellant’s submissions that D2 was wholly irrelevant as a non-analogous prior art and that D3 was a distinct process dealing with generic electrode composition not disclosing or suggesting the process sequence or material synthesis route of the instant patentand that the combined teachings of D1, D2and D3 would not lead a person skilled in the art to the claimed invention without impermissible mosaicking and hindsight. The Court found there was no determination of these issues in the impugned order.
On the ground of insufficient disclosure under Section 25(2)(g), the Court held that the impugned order had misapplied the test of sufficiency of disclosure. The Court affirmed that the sufficiency requirement is met if at least one way of working the invention is clearly described enabling a skilled person to carry out the inventionand there is no need to provide examples over the entire scope claimed. The Court further found that the impugned order at more than one place stated that despite opportunity to the appellant to furnish experimental data it had failed to do so, but records called for by the Court did not substantiate this observation. The Court also noted that the appellant had filed an application to place additional experimental data on record before this Court, which was allowed, since the data was crucial for just adjudication of the post-grant opposition.
On the appropriate remedy, the Court held that this was a fit case for remand rather than a case where the Court should express any opinion on the merits. Accordingly, Respondent No. 1 was directed to consider the post-grant opposition afresh, taking into account the additional documents allowed by this Court, all issues raised by the appellant in its reply to the opposition notice and detailed written submissions already on record, all issues raised in the present appealand all submissions raised in the opposition. The fresh decision was directed to be taken after hearing both parties, within a period of four months from the date of the order. The Court expressly made clear that it had not expressed any opinion on the merits of the case. The appeal was disposed of accordingly along with the pending application.

STATUTORY PROVISIONS INVOLVED

Section 25(2)(e) of the Patents Act, 1970 provides that any person may, at any time after the grant of a patent but before the expiry of a period of one year from the date of publication of grant of a patent, give notice of opposition to the Controller on the ground that the invention, so far as claimed in any claim of the complete specification, is obvious and clearly does not involve any inventive step, having regard to the matter published as mentioned in Section 25(2)(b) or having regard to what was used in India before the priority date of the applicant’s claim. This was the principal ground on which the post-grant opposition was sustained by Respondent No. 1 and challenged by the appellant in the present appeal. The Court held that the evaluation of this ground by Respondent No. 1 was vitiated by non-compliance with the mandatory five-step test for determining inventive step and by resort to hindsight reasoning.

Section 25(2)(g) of the Patents Act, 1970 provides that the ground of opposition may include that the complete specification does not sufficiently and fairly describe the invention or the method by which it is to be performed, i.e., that the description of the method or the instructions for the working of the invention as contained in the complete specification are not by themselves sufficient to enable a person in India possessing average skill inand average knowledge of, the art to which the invention relates to work the invention or that it does not disclose the best method of performing it which was known to the applicant for the patent and for which he was entitled to claim protection. This ground was also upheld by Respondent No. 1 in the impugned order. The Court found that the impugned order had misapplied the test of sufficiency under this provision and that the factual basis for the observation that the appellant had not provided experimental data despite opportunity was not substantiated by the records called for by the Court.

Section 25(2)(b) of the Patents Act, 1970 provides that an opposition may be filed on the ground that the invention as claimed is anticipated by prior publication. This ground was rejected by Respondent No. 1 as non-sustainable and was not in issue in the present appeal.

Section 117A of the Patents Act, 1970 provides for appeals to the High Court against decisions of the Controller of Patents. The present appeal was filed under this provision by the appellant challenging the order of revocation passed by Respondent No. 1 on 18.10.2024.

Section 2(1)(ja) of the Patents Act, 1970 defines “inventive step” as a feature of an invention that involves technical advance as compared to the existing knowledge or having economic significance or bothand that makes the invention not obvious to a person skilled in the art. The Court relied on this definition and the decision in Agriboard International LLC to hold that a mere conclusion of lack of inventive step without following the mandatory analytical steps is contrary to this provision.

REASONING OF THE COURT

The Court’s reasoning was structured around two distinct but related failures in the impugned order: the procedural failure to follow the mandatory five-step test for inventive stepand the substantive failure to properly consider the appellant’s specific arguments regarding the distinctions between the claimed invention and the cited prior arts.

On the procedural failure, the Court found the position settled beyond debate by the Division Bench in F. Hoffmann-La Roche and affirmed by another Division Bench in Tapas Chatterjee: the five steps must be applied sequentially. The first step identification of the ordinary person skilled in the art was entirely absent from the impugned order. The fifth step determining whether the identified differences would have been obvious to such a personand excluding hindsight was also not followed. The Court found that instead of conducting this structured analysis, Respondent No. 1 had essentially worked backwards from the claimed invention using it as a blueprint to dissect the individual steps and then sought them individually in the prior arts. This is the classic hallmark of hindsight reasoning, which the five-step test is specifically designed to prevent.

On the substantive failure, the Court identified several important differences flagged by the appellant in the process of IN’806 as compared to D1 that Respondent No. 1 had not properly considered. The Court noted that the starting material in D1 undergoes mandatory pre-treatment steps including sink and float treatment that are entirely absent in the subject patent; that charring, which is a mandatory and essential step in D1 whose key purpose is to lock carbon into an insoluble matrix, is entirely absent in the claimed invention; that the material subjected to acid treatment in D1 is charred material treated with HCl at 80°C to 120°C whereas in the subject patent it is uncharged material treated with HF at 25°C to 60°C; and that HF removes SiO2 and metallic impurities in a manner that HCl in D1 cannot achieve. Respondent No. 1 had simply posed rhetorical questions about whether higher yield had been demonstrated, without engaging with these technical distinctionsand had drawn conclusions adverse to the appellant without addressing the negative teaching in D1 that the process would not work without charring.

On the insufficiency ground, the Court found a specific factual error in the impugned order. The impugned order repeatedly stated that the appellant had failed to provide experimental data despite having been given the opportunity to do so. However, when the Court called for the records to verify this observation, the records did not substantiate it. This was a significant infirmity since the entire conclusion on insufficiency rested in part on the premise that the appellant had been afforded and had squandered an opportunity to furnish the data. Since that premise was not borne out by the recordand since the appellant had now placed additional experimental data before this Court which was allowed into evidence, the Court found that the matter required fresh consideration with the benefit of this data before Respondent No. 1.

The Court’s decision to remand rather than decide the matter on merits was consistent with its express statement that it had not expressed any opinion on the merits of the case. The remand was structured to ensure that Respondent No. 1 would consider all issues comprehensively the additional documents, the appellant’s reply and written submissions already on record, the issues raised in the appealand all submissions made in the opposition and that a fresh decision after hearing both parties would be rendered within four months.

DOCTRINAL SIGNIFICANCE

This judgment makes a practically significant contribution to the jurisprudence governing the conduct of post-grant opposition proceedings under the Patents Act, 1970, particularly in relation to the mandatory analytical framework for determining inventive step and the standard of sufficiency of disclosure.

The most important doctrinal contribution is the Court’s firm reiteration drawing on the Division Bench precedents in F. Hoffmann-La Roche and Tapas Chatterjee that the five-step test for evaluating inventive step is mandatory and must be followed sequentially by the Controller. The failure to identify the person skilled in the art at the very first step is not a mere procedural irregularity but a fundamental error that vitiates the entire inventive step analysis, because all subsequent steps in the analysis identifying the inventive concept, identifying differencesand determining obviousness are to be conducted from the perspective of that notional person. Without this anchor, the analysis defaults to hindsight reasoning, which is precisely what the structured five-step test is designed to prevent.

The judgment also reinforces the principle, drawn from Agriboard International LLC, that a mere conclusion of lack of inventive step without working through the mandatory analytical steps is contrary to Section 2(1)(ja) of the Patents Act. Controllers deciding post-grant oppositions are required to engage with the specific technical arguments made by the patentee, particularly where those arguments concern negative teaching in the prior art, differences in the sequence and nature of process stepsand the non-analogous character of prior art documents sought to be combined.

On the sufficiency of disclosure ground, the Court’s willingness to call for the records and verify whether the factual basis for the impugned order’s observation was borne out is a noteworthy exercise of appellate scrutiny. The finding that the records did not substantiate the observation that the appellant had been given and had failed to use an opportunity to furnish experimental data is a salutary reminder that conclusions in post-grant opposition orders must be grounded in the actual record of proceedings before the Patent Office.

The judgment further confirms, consistent with the law as settled, that sufficiency of disclosure under Section 25(2)(g) is established if at least one way of working the invention is clearly described enabling a skilled person to carry out it there is no requirement to provide examples covering the entire scope of the claims. The broadening of the claims in Claims 2 and 3 beyond the specific examples in the detailed description will not by itself constitute insufficiency, though this will remain a matter for Respondent No. 1 to evaluate afresh in the remand proceedings.

The judgment must be read as a remand order and not a decision on the merits. The Court expressly declined to express any opinion on whether IN’806 lacks inventive step or is insufficient, leaving those questions entirely open for fresh determination by Respondent No. 1 within four months of the order.

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