Lithium Metal Anode Patents — Why Is It Still Too Early?

What Is the Issue: Lithium Metal Anode Patents That Stop at “Suppression”

Lithium metal anode patents are growing in number, but the published claims remain technologies that “guide dendrites to grow evenly” rather than technologies that “eliminate” them. That is why it is still too early to treat patents in this field as a basis for business decisions. This article explains why by placing side by side the lithium metal anode protective-layer patent announced on January 30, 2026 by mobility platform company IL and the granted patent KR102340319B1 held by GreennerG.

Starting with the industry landscape, lithium metal is regarded as the “ultimate anode material,” because instead of storing lithium between layers as graphite does, lithium metal itself becomes the anode. An academic review puts the theoretical specific capacity of lithium metal at 3,860 mAh/g and its potential at −3.04 V versus the standard hydrogen electrode, explaining that its theoretical specific capacity is about 10 times that of a commercial graphite anode (372 mAh/g). For cell makers seeking higher energy density, it is the most attractive option.

The source of tension is the dendrite (lithium growing in the shape of branches or needles during charging). When a dendrite pierces the separator and reaches the cathode, it can lead to internal short circuits and fire, which is why it remains the biggest obstacle to commercialization. This article answers three questions: at which layer do the two patents address the dendrite problem, how far does the scope of rights of each claim reach, and when and with what weight should planning and IP staff evaluate patents in this field?

Basic Principle: Two Ways to Make Snow Pile Up Evenly

In a lithium metal anode, lithium ions are deposited as metal on the anode surface during charging. When the deposition is uniform, the surface thickens evenly, but when current concentrates at particular spots, lithium rises only there and becomes a dendrite. The two patents address this non-uniform deposition at different layers.

By analogy, lithium deposition resembles snow piling up on a roof. The first method is to smooth the roof surface itself so that snow does not gather in one spot. The approach of forming a protective layer on the surface of the copper current collector to guide lithium to settle uniformly, as in IL’s patent, falls here. The second method is to cover the roof with a fine net so that even if a column of snow rises, it cannot break through the net. The approach of placing an inorganic nanoparticle layer on the separator side to physically block growth, as in KR102340319B1, falls here.

• Protective layer on the current collector side: a strategy that stabilizes the interface of the floor on which lithium first settles, making deposition itself uniform.
• Inorganic layer on the separator side: a strategy that places a physical barrier so that protrusions that have already formed cannot penetrate the separator.

Both methods only lower the probability of dendrite formation and the rate of growth; they do not change the fundamental condition that lithium is deposited as metal. This point connects directly to the limits of the claim language examined below.

Comparison: The Approaches and Maturity of the Two Patents

The table below arranges, in a single framework, the basic figures for graphite and lithium metal anodes and the approaches of the two patents. Because the number of IL’s patent was not disclosed in press reports, only its title and the reported content are listed.

Item	Graphite anode	Lithium metal + current-collector protective layer (IL)	Lithium metal + inorganic-layer separator (KR102340319B1)
Theoretical specific capacity	372 mAh/g	3,860 mAh/g (lithium metal)	3,860 mAh/g (lithium metal)
Where dendrites are addressed	Not applicable (interlayer storage)	Copper current collector–lithium interface	Lithium metal–separator interface
Key material	Graphite	Protective layer based on lithium transition metal oxide	Inorganic nanoparticle layer of 5–200 nm
Right status	Not applicable	Grant announced (2026-01-30), number undisclosed	Granted (2021-12-21), Active
Nature of claim language	Not applicable	Guiding uniform deposition (per press reports)	Structural limitation (particle size, layer position)

What this table says: lithium metal has about 10 times the theoretical specific capacity of graphite (3,860 vs. 372 mAh/g), but both patents are interface technologies that “protect” that potential, and they act at different positions, the current collector side and the separator side. In other words, the two rights are less competitors than technologies at layers that could be stacked within a single cell.

Patent Perspective: The Claims Promise Only “Suppression”

KR102340319B1 (title: Lithium metal anode structure, electrochemical device including the same, and manufacturing method thereof) was filed by GreennerG Co., Ltd. on October 25, 2019, published as KR20210050059A on May 7, 2021, and granted on December 21, 2021. According to Google Patents, its legal status is Active and its anticipated expiration date is October 25, 2039.

Restated, the gist of claim 1 is as follows. There is a lithium metal anode, and a separator is attached to at least one surface of it. This separator includes a porous substrate and an inorganic layer made of inorganic nanoparticles 5–200 nm in size coated on that substrate, and the inorganic layer is positioned between the lithium metal anode and the porous substrate. The specification explains that the structure is made with a rolling roll or press to make the electrode surface uniform and increase adhesion between the inorganic layer and the metal electrode, suggesting a link with roll-to-roll (R2R, continuous rolling) processing.

IL’s patent (title: Negative electrode for lithium secondary battery including a protective layer, manufacturing method thereof, and lithium secondary battery including the same) was reported to center on forming a functional protective layer based on lithium transition metal oxide on the surface of a copper current collector to guide uniform lithium deposition. IL later announced in June 2026 that it had filed a patent covering a dual-functional protective layer and a roll-to-roll continuous manufacturing method, and stated that it had reduced current-density variation from ±45% to ±3% or less. However, this figure is a company announcement and has not been confirmed in a published application.

Insight: the scopes of the two patents diverge at “anode-free” design. Claim 1 of KR102340319B1 requires as elements a “lithium metal anode” and a separator attached to it. Therefore, an anode-free cell, which is assembled with only a current collector and no lithium metal and deposits lithium on the first charge, may lack this element if one looks only at the manufacturing stage. Conversely, IL’s approach of placing a protective layer on the current collector surface sits at a position that works just as well in an anode-free cell, so as anode-free design spreads, the reach of rights to current-collector-side protective layers may become relatively broader. However, whether infringement risk is judged based on the state in which lithium metal has formed in the cell after charging may vary depending on claim construction and the embodiment.

Design-around points: KR102340319B1 limits the inorganic nanoparticle size to 5–200 nm and fixes the position of the inorganic layer as “between the lithium metal anode and the porous substrate.” On the literal wording, a design using particles larger than 200 nm, or one placing the inorganic layer only on the cathode-facing side, may fall outside this element. A configuration in which the separator is not “attached” to the anode but stacked as an independent component is also a subject of review.

Design-around scenario (counterargument): However, if the particle size distribution is broad and part of it falls within the 5–200 nm range, a literal infringement claim may be raised, and if a design that merely reverses the position of the inorganic layer achieves the same dendrite-blocking function in the same way, it may become subject to a doctrine-of-equivalents analysis. From the patentee’s side, because ceramic-coated separators themselves are an old technology, the validity of claim 1 may be contested in comparison with prior coated-separator literature. Ultimately, FTO (freedom-to-operate review) must be judged by setting the particle-size measurement method and the prior art side by side.

Limits and Outlook

In both patents, the claim language and the purpose of the invention are aimed at “suppressing dendrite growth” and “guiding uniform deposition.” No claim at the level of fundamentally blocking dendrites is confirmed anywhere in the published materials. This means the patent language itself reveals that these technologies are not complete solutions but technologies that lower risk. IL also presents all-solid-state batteries, humanoid robots and drones as applications, showing that it has combination with solid electrolytes, rather than liquid electrolytes, in mind.

The optimistic outlook is that, as protective-layer and inorganic-layer technologies accumulate and are combined with solid electrolytes, lithium metal anodes will move into commercial cells. There is also a counter-scenario. Even if interface technologies show effects over laboratory-scale cycling, if non-uniform deposition accumulates in large-area, long-term cycling, they may be held back at the safety certification stage. In that case, many of the interface patents granted today could use up a substantial part of their term before being practiced in actual products.

The time axis must be considered as well. The anticipated expiration date of KR102340319B1 is October 25, 2039. The later full-scale mass production of lithium metal anode cells arrives, the shorter the period in which this patent can be asserted against actual products. Conversely, companies seeking to bring mass production forward need designs that secure distance from claim 1 during this period. Ultimately, the value of lithium metal patents depends not only on technical merit but on how much the commercialization timing overlaps with the patent term.

The strategic alternative is to classify and track lithium metal patents by “position and process” rather than “material composition.” Depending on whether the protective layer is on the current collector side or the separator side, and whether a continuous process such as roll pressing is claimed, the rights that survive a transition to anode-free or all-solid-state cells differ.

Practical action: Planning and IP staff reviewing lithium metal or anode-free cells should first confirm the registration number and original claim text of IL’s patent on KIPRIS, and then prepare an element comparison chart together with KR102340319B1 along three items: protective-layer position (current collector/separator), particle size, and whether lithium is present at assembly.

Items requiring verification

• The registration number, filing date and original claim text of the granted patent IL announced in January 2026
• The measurement conditions for the current-density variation improvement IL stated (±45% → ±3% or less)
• Whether KR102340319B1 has foreign family filings (US, EP, CN, etc.)
• The specific numbers and claim scope of the LG Energy Solution lithium metal anode patents mentioned in the original article

Sources

1. Google Patents, KR102340319B1 – Lithium metal anode structure, electrochemical device including the same, and manufacturing method thereof (GreennerG Co., Ltd.)
2. Newspim, “IL registers core patent for suppressing dendrites in lithium metal batteries” (2026-01-30)
3. Money Today, “IL registers core patent for suppressing dendrites in lithium metal batteries” (2026-01-30)
4. Edaily, “IL files core patent on source technology for continuous mass production of lithium metal anodes” (2026-06-16)
5. Ding J.-F. et al., “Review on lithium metal anodes towards high energy density batteries”, Green Energy & Environment (2023)

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