Introduction
In a notable decision emphasizing fair and reasoned decision-making in patent matters, the Delhi High Court set aside an order revoking a patent for a sustainable process to make hard carbon electrode material from cattle manure. The court did not decide whether the invention deserved a patent but sent the case back to the Patent Office for fresh consideration. It held that the Deputy Controller failed to properly apply the established legal test for checking if an invention involves an “inventive step” (something non-obvious to a skilled person).
The ruling highlights how Indian courts expect patent authorities to carefully evaluate prior art documents, identify the skilled worker in the field, and avoid deciding with the benefit of hindsight. It also allowed additional experimental data to be considered, stressing that justice requires looking at all relevant evidence. Delivered on 12 March 2026 by Justice Jyoti Singh, the judgment protects innovators working on green technologies while reminding authorities to follow due process.
Factual Background
Indigenous Energy Storage Technologies Pvt. Ltd., the appellant, is a company focused on sustainable energy storage, especially sodium-ion battery technology. It developed a process to turn cattle manure and other bio-waste into hard carbon, a key material used as an electrode in sodium-ion batteries and supercapacitors.
Key Benefits of the Invention
- Low-cost production method
- Environmentally friendly (repurposing agricultural waste)
- Scalable for industrial use
- Delivers good technical performance
The patent application (leading to Indian Patent No. 373806 or IN’806) was filed on 4 November 2020, examined, and granted on 4 August 2021. The title of the patent is “Cattle Manure Derived Hard Carbon as Electrode Material for Sodium Ion Batteries and Super Capacitors.”
Process Description (Claim 1)
- Drying the manure at 50–100°C
- Grinding the material
- Treating it with acid solutions (like hydrofluoric acid) under specific conditions
- Washing the treated material
- Vacuum drying
- High-temperature calcination in a controlled environment
Dependent Claims
- Variations in the type of manure used
- Use in different metal-ion batteries
- Specific composite electrode formulation
Procedural Background
Soon after the grant, a post-grant opposition was filed on 3 August 2021 under Section 25(2) of the Patents Act, 1970, challenging the patent on grounds including lack of novelty, lack of inventive step (Section 25(2)(e)), and insufficient disclosure (Section 25(2)(g)).
Prior Art Documents Relied Upon
| Document | Description |
|---|---|
| D1 | WO publication on processing animal-derived waste for hard carbon |
| D2 | Textbook on physical chemistry showing water phase diagrams |
| D3 | US patent on electrode materials for sodium-ion batteries |
The Patent Office heard the parties and, on 18 October 2024, revoked the patent. It rejected the novelty objection but upheld lack of inventive step (finding the process obvious over D1, combined with D2 and D3) and insufficient disclosure (citing lack of experimental data on yield, purity, and scalability).
Appeal Before Delhi High Court
The patentee filed an appeal under Section 117A of the Patents Act before the Delhi High Court. During the appeal, it also moved an application to place additional evidence on record, including:
- An expert opinion distinguishing the invention from prior art
- Data showing superior yield
- A letter about the revocation order
The High Court allowed this additional evidence, citing the Supreme Court judgment in Union of India v. Ibrahim Uddin (2012) 8 SCC 148, as it would help in just adjudication.
Reasoning
The High Court examined whether the Controller’s revocation order was legally sound. It found serious procedural and substantive flaws.
Inventive Step Analysis And Legal Flaws
First, the court stressed that deciding inventive step is not a simple comparison of documents. Indian law requires following a structured five-step test laid down by the Delhi High Court in the F. Hoffmann-La Roche v. Cipla case. The Controller failed to identify the “person skilled in the art” (a skilled but unimaginative worker in battery materials or biomass processing), did not clearly define the inventive concept of the patent, and did not properly analyse differences between the claimed process and prior art without using hindsight.
Key Differences Highlighted In The Patent
The court noted that the appellant had highlighted key differences:
- The patent skips the expensive “charring” step mandatory in D1
- Uses hydrofluoric acid (HF) at lower temperatures (25–60°C) instead of HCl at higher temperatures
- Avoids certain pre-treatments like “sink and float”
- Employs specific vacuum drying conditions
These steps allegedly lead to:
- Better purity
- Higher yield
- A material better suited for sodium-ion batteries
The controller dismissed many points by saying the patentee did not prove “technical advantage” or provide enough experimental data, but the court found this approach flawed and hindsight-driven.
Combination Of Prior Art Analysis
On the combination of prior arts, the court observed that D2 (a general chemistry textbook on water phases) and D3 (electrode formulations) appeared non-analogous to the biomass-to-hard-carbon process in D1. Mosaic combinations (piecing unrelated documents together) are not freely allowed unless the prior art itself suggests the combination with a reasonable expectation of success.
Insufficient Disclosure Under Section 25(2)(g)
Regarding insufficient disclosure under Section 25(2)(g), the court held that the specification sufficiently described at least one way to work the invention, which is generally enough. Doubts about industrial scalability based on laboratory yields should not lead to revocation without giving the patentee a proper chance to submit supporting data.
The court verified that the Controller’s claim of providing opportunities for data was not fully supported by records. It therefore allowed the additional experimental data filed in the appeal.
Court’s Overall Conclusion
Overall, the High Court found the impugned order lacked proper reasoning and failed to follow mandatory legal procedures for assessing inventive step and sufficiency. It emphasised that patent decisions must be speaking orders that address all key arguments raised by the parties.
Key Judgments Discussed With Citations And Context
The court relied on several important precedents to guide its analysis, explaining them in a way that shows how they apply to everyday patent examination:
| Case Name | Citation | Key Principle | Relevance In Present Case |
|---|---|---|---|
| F. Hoffmann-La Roche Ltd. & Anr. v. Cipla Ltd. | 2015 SCC OnLine Del 13619 | Laid down a five-step test for inventive step/obviousness under Section 2(1)(ja) | The controller failed to follow structured test, making decision legally flawed |
| Tapas Chatterjee v. Assistant Controller of Patents and Designs and Another | 2025 SCC OnLine Del 6369 | Reaffirmed that Hoffmann-La Roche test must be followed sequentially | Failure to identify skilled person alone justified setting aside the order. |
| Agriboard International LLC v. Deputy Controller of Patents and Designs | 2022 SCC OnLine Del 940 | Requires detailed reasoning in patent rejection orders | Used to criticize superficial reasoning in impugned order |
| Union of India v. Ibrahim Uddin and Another | (2012) 8 SCC 148 | Allows additional evidence in appeal for just adjudication | Supported admission of expert opinion and yield data |
Legal Principles Emphasized By The Court
- Follow structured legal tests for inventive step
- Avoid hindsight bias in patent analysis
- Provide detailed, reasoned (“speaking”) orders
- Consider all relevant evidence before revocation
- Ensure procedural fairness in patent examination
Final Decision Of The Court
The Delhi High Court allowed the appeal and set aside the revocation order dated 18 October 2024. It remanded the post-grant opposition back to the deputy controller for fresh consideration. The Controller must now examine the matter afresh, taking into account the additional documents allowed by the High Court, all issues raised by the appellant in its reply and written submissions, and the arguments in the appeal.
Both parties must be heard, and a decision should be taken within four months. The court clarified that it expressed no opinion on the merits of the patent’s validity, leaving that entirely to the Patent Office.
Point Of Law Settled In The Case
This judgement reinforces simple but important principles for anyone dealing with patents in India:
Inventive Step (Obviousness Test)
When checking if an invention is obvious (lacks inventive step), the Patent Office must follow a clear, step-by-step process:
- Identify who the skilled worker is
- Determine what the new idea really is
- Assess what everyone in the field already knew
- Identify what is different from old inventions
- Evaluate whether those differences would have been obvious without hindsight
Skipping these steps or using hindsight makes the decision invalid.
Sufficiency Of Disclosure
Additionally, when sufficiency of disclosure is challenged, the specification needs only to describe at least one clear way for a skilled person to carry out the invention — not prove every possible use with extensive data upfront.
- At least one workable method must be disclosed
- Extensive experimental data is not mandatory at filing stage
- Authorities should allow submission of additional data if required later
If more data becomes relevant later, authorities should give the patentee a fair opportunity to submit it rather than revoking the patent outright.
Additional Evidence In Appeals
Finally, courts can allow additional evidence in appeals if it helps reach a just decision, especially in technical fields like green energy where experimental proof of advantages matters.
- Courts have discretion to admit additional evidence
- Particularly important in technical and scientific matters
- Helps ensure fair and just adjudication
Requirement Of Reasoned Decisions
Patent decisions must be detailed and address all key arguments raised by the parties; vague or incomplete reasoning will not stand.
| Requirement | Explanation |
|---|---|
| Detailed Reasoning | All arguments must be properly addressed |
| No Vague Orders | Unclear reasoning can invalidate decisions |
| Consideration Of Evidence | All relevant materials must be evaluated |
Impact On Innovation
The ruling encourages innovation in sustainable technologies by ensuring patent challenges are handled with proper legal rigour and fairness.
Case Details
| Particulars | Details |
|---|---|
| Case Title | Indigenous Energy Storage Technologies Pvt. Ltd. vs. Deputy Controller of Patents and Designs & Anr. |
| Date Of Order | 12 March 2026 |
| Case Number | C.A. (COMM.IPD-PAT) 3/2025 |
| Name Of Court | High Court of Delhi |
| Name Of Honourable Judge | Justice Jyoti Singh |
Disclaimer: Readers are advised not to treat this as a substitute for legal advice, as it may contain errors in perception, interpretation, and presentation.
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
