① What’s the Story
We previously covered, in an earlier trends article, the news that radioisotope batteries (nuclear batteries) have actually begun flying in orbit as power sources for commercial satellites. This article goes a step further and compares, claim by claim, how the patents held by U.S. and Chinese companies around this technology have actually designed their rights. The subjects are US12094620B2 from U.S.-based City Labs and CN119207858A from Beijing BetaVolt New Energy Technology Co., Ltd. (北京贝塔伏特新能科技有限公司), based in China. For both patents, the applicant, priority date, registration/publication status, and claim elements were confirmed directly from the original text on Google Patents.
② Basic Principle
Both patents share the same goal of “converting beta particles from a radioisotope into electricity,” but the design of the path to reach that goal is entirely different. To use an analogy, City Labs’ approach is like sending electricity generated at a power plant straight out onto the transmission lines, while BetaVolt’s approach is like first storing the electricity generated at the power plant in a battery warehouse (a supercapacitor) and drawing it out when needed. This difference is not merely a matter of design taste — it is the element that divides what the claims actually protect.
Source: reconstructed by the editorial team from the claims of US12094620B2 and CN119207858A (Google Patents)
③ Comparison: The Claim Structure of the Two Patents
| Category | US12094620B2 (City Labs) | CN119207858A (BetaVolt) |
|---|---|---|
| Invention title | Epitaxial liftoff-layer semiconductor device for direct conversion of radioisotope emission into power | Isotope power source and its manufacturing method |
| Applicant | City Labs Inc (U.S.) | Beijing BetaVolt New Energy Technology Co., Ltd. |
| Inventor(s) | Peter Cabauy | Multiple Moscow-based inventors (based on a Russian priority application) |
| Priority date | 2014-02-17 (basis date of the continuation application) | 2023-07-26 (based on Russian application RU2023119639A) |
| Filing date | 2023-09-18 (U.S. continuation filing) | 2024-01-31 (China) |
| Grant/publication date | Granted 2024-09-17 | Published 2024-12-27 (not yet granted) |
| Legal status | Active (valid registration) | Pending (under examination) |
| Core claim elements | A multilayer semiconductor stack that captures beta particles on a doped semiconductor substrate (Ge, GaAs, etc.), capable of series/parallel connection | Combination of a β-radiation source + a diamond semiconductor converter + a supercapacitor with carbon-nanotube nonwoven-fabric electrodes and a sulfuric acid electrolyte |
| Expected expiration (based on grant) | 2035-02-17 | Cannot be calculated as unregistered (typically filing date + 20 years upon grant) |
Source: compiled by the editorial team from the bibliographic data and claims of US12094620B2 and CN119207858A (Google Patents)
What This Table Tells Us: City Labs has claimed ‘the semiconductor device itself’ narrowly and deeply, and has already secured a grant, whereas BetaVolt is claiming a system combination of ‘isotope source + converter + storage device,’ which reads as aiming for a relatively broader claim scope even though it is still at the application stage.
④ Patent Perspective
From a claim-scope perspective, City Labs’ claim pins down a semiconductor stack structure (a stack combining GaAs, InAlP, InGaP, InAlGaP, AlGaAs, and the like on a doped germanium or gallium arsenide substrate) as its core element. This style of claiming, which lists numerous alternative materials, is a typical ‘family claiming’ strategy that makes it difficult for a competitor to escape literal infringement merely by swapping one particular semiconductor for another material. That said, since this claim presupposes a stack structure manufactured through an epitaxial liftoff process, there is room to argue a failure to meet the claim elements if a party instead chooses a path that produces a similar multilayer structure through a different manufacturing process (for example, bulk growth followed by slicing).
It should first be noted that because BetaVolt’s CN119207858A is still a pending application, its registered claims have not yet been finalized. Looking at the currently published claim intent, it claims, at the system level, a combination of two elements — a ‘diamond semiconductor converter’ and a ‘supercapacitor with carbon-nanotube electrodes and an aqueous sulfuric acid electrolyte’ — a structure in which the absence of either component reduces the possibility of infringement due to a failure to meet the claim elements. For example, a design that uses only the diamond converter without a supercapacitor, or one that uses a supercapacitor but adopts an electrode material other than carbon nanotubes, may fall outside the currently published claim scope. However, since the claim scope may still be amended or broadened during examination, this is only a provisional assessment as of the present time.
A cross-check of similar patents confirms that City Labs has been continuously accumulating numerous related applications in the same technology area (betavoltaic semiconductor devices), including US10607744B2, US11462337B2, and US20150310952A1, suggesting that the defensive line is formed not by a single patent but by the entire patent family. For a latecomer to enter this space, avoiding a single individual patent is not enough — a Freedom to Operate (FTO) review covering the entire family is effectively essential.
⑤ Limitations and Outlook
It is premature to conclude that City Labs has preempted the standard for this market merely because it holds both a granted patent and an actual satellite deployment track record. As a counter-scenario, BetaVolt and other Chinese companies could instead compete on volume by first dominating the low-cost terrestrial market (IoT sensors, unmanned polar and ocean observation equipment, and the like) using relatively inexpensive, long-half-life isotopes such as nickel-63. In this case, the high-performance space market and the low-cost terrestrial market could end up split between different players.
As a strategic alternative, rather than viewing the two companies’ patent strategies as a strict either/or, it is worth examining the room for a separate patent covering a design that combines direct semiconductor conversion (the City Labs type) and a conversion-storage hybrid (the BetaVolt type) by use case — for example, a dual approach using direct conversion for continuous low-power sections and the storage type for sections requiring momentary high current. This is a design space with a relatively higher likelihood of not directly colliding in claim scope with either of the two existing patent families.
Action for planning and IP personnel: if you are reviewing a power module for extreme environments or long-term unmanned use, create an internal design comparison table that maps your own design item-by-item against City Labs’ patent family (the epitaxial liftoff series) and the claim scope of BetaVolt’s CN119207858A, and be sure to cross-check it during your internal IP review stage before finalizing the materials and structure.