Electrolyzer maintenance is essential for ensuring the long-term, stable operation of equipment and involves the periodic inspection and replacement of electrodes, separators, sealing systems, electrolyte circulation systems, and electrical connections. Due to differences in operating principles, material systems, and operating conditions across various industries, maintenance strategies and frequencies for electrolyzers vary significantly. The European Industrial Gases Association (EIGA) explicitly requires that pipes, valves, pumps, heat exchangers, and collection tanks in alkaline electrolyzers be inspected frequently for electrolyte or water leaks. The American Institute of Chemical Engineers (AIChE) notes that the Compressed Gas Association (CGA) is developing new standards that include best practices for the safe operation and maintenance of electrolyzers. Within thyssenkrupp nucera’s 360° full lifecycle service portfolio, the Electrolyzer Maintenance Switch (EMS) significantly enhances the safety and efficiency of electrolyzer maintenance by reducing residual voltage. The core logic of electrolyzer maintenance is divided into three levels: daily cleaning and condition monitoring constitute Level 1 life-extension measures; scheduled overhauls involving the replacement of gaskets and the recoating or replacement of electrodes constitute the second-level performance restoration; and when cell voltage abnormally rises or current efficiency significantly drops, the targeted replacement of faulty cells constitutes the third-level condition-based replacement.
| Industry/Electrolyzer Type | “Core” Components Requiring Periodic Replacement | Secondary Replacement Components (Moderate Replacement Intervals) | Consumable Accessories (Frequent Replacement) |
|---|---|---|---|
| 1. Hydrogen Production Plant (ALK) | Diaphragm (5–8 years; thinning or perforation) Electrode Coating (5–10 years; nickel-based coating peeling off) | Sealing Gaskets (3–5 years; hardening due to caustic solution corrosion) Electrodes (if perforated due to localized corrosion) | Electrolyte (KOH) (filter or replace every 2–3 years) Alkaline solution filter cartridge (several months) |
| 2. Hydrogen Production Plant (PEM) | Membrane Electrode Assembly (MEA) (3–5 years, membrane degradation or catalyst agglomeration) Titanium bipolar plate coating (5–8 years, increased resistance due to passivation) | Deionized water resin/filter cartridge (several months–1 year) Sealing rings (2–3 years) | Anode/cathode gas diffusion layers (if locally ablated) |
| 3. Chlor-Alkali Plant | Cation Exchange Membrane (~3 years, the core of the core) Electrode Coating (5–8 years, re-coating with ruthenium/iridium oxides) | Sealing Gaskets (2–3 years, replacement of the entire cell) Titanium Anode Mesh (if substrate corrosion occurs after coating failure) | Refined Brine Filter (frequent) |
| 4. Metal Smelting (Molten Salt Electrolysis, e.g., Aluminum) | Prebaked Carbon Anodes (Replace one set every 20–30 days; continuous consumption) Carbon Cathode Lining (3–5 years; if the bottom is damaged) | Side Carbon Blocks (Replaced during major overhauls) Steel Claws/Guide Rods (if bent or corroded) | Alumina Powder (continuous feeding; not a component replacement) |
| 5. Metal Smelting (Aqueous Solutions, e.g., Copper/Zinc) | Cathode starter plates/permanent cathodes (if deformed or insulation layer damaged) Insoluble anodes (lead/titanium-based) (2–5 years, passivation) | Conductive contacts (poor contact due to wear) Diaphragm bags (if present, approximately 2 years) | Electrolyte purification resin (to remove impurity ions) |
| 6. Electroplating/Precision PCB Electroplating | Soluble anodes (e.g., copper balls/nickel blocks) (replenish when depleted) Insoluble anodes (coated titanium mesh) (1–3 years, upon coating failure) | Heating elements (scaling and burnout, 1–2 years) Filter cartridges (weeks to months, frequent replacement) | Plating bath additives (continuous replenishment) Hanging fixtures/clamping fixtures contacts (months) |
| 7. Wastewater Treatment/Disinfection and Preparation | Electrode plates (6–12 months; due to scaling, passivation, or corrosion; considered consumables) | Rectifiers (repaired, not replaced) Pipes and valves (if corroded by sodium hypochlorite) | Pickling solution (used for chemical cleaning; not a component) |
Many of the components replaced periodically in electrolytic cells have recycling value, and DONGSHENG Precious Metals Recycling Company purchases these components at high prices.
Alkaline electrolyzer (ALK) technology is the most mature and cost-effective option for hydrogen production plants, and electrolyzer maintenance focuses on three key areas: leak prevention, clog prevention, and corrosion prevention. The sealing gaskets in ALK electrolyzers harden and fail within 3–5 years in a high-temperature alkaline solution environment; they must be completely replaced, and it is recommended to upgrade to fluorocarbon rubber (FKM) material. The separator must be replaced after 5–8 years if it thins or develops holes, leading to hydrogen-oxygen cross-contamination. During shutdowns, the system must be purged with nitrogen, sealed to prevent CO₂ ingress, and the electrolyte must be flushed and circulated to prevent carbonate deposits. Proton-exchange-membrane (PEM) electrolyzers respond quickly and are better suited for fluctuating power sources; maintenance of these electrolyzers focuses on protecting the membrane and catalyst. Membrane electrode assemblies (MEAs) must be replaced every 3–5 years due to membrane degradation or catalyst agglomeration. At high current densities (e.g., 3 A/cm²), voltage drift can reach 50.0 μV/h, far exceeding that observed under low-current conditions. Real-time monitoring combined with electrochemical impedance spectroscopy (EIS) is widely recognized as a key strategy for the early detection of degradation. Solid oxide electrolyzers (SOEC) and anion-exchange membrane electrolyzers (AEM) are mostly in the R&D and demonstration stages, and their maintenance relies more heavily on manufacturer-specific solutions. Ion-exchange membrane electrolyzers have become the absolute mainstream in chlor-alkali plants, while the diaphragm and mercury processes are being phased out due to pollution concerns. The ion exchange membrane is the top priority in electrolyzer maintenance, with a service life of approximately three years. Membrane replacement involves a comprehensive process, including shutting down and isolating the electrolyzer, removing copper busbars, dismantling the old membrane and gaskets, grinding the electrolyzer, applying new gaskets, soaking and conditioning the membrane, and finally installing the membrane assembly. The Nafion™ membrane installation guide emphasizes that pinholes or tears must be prevented during installation, and the membrane must never be allowed to dry out during shutdowns or periods of inactivity. Molten salt electrolysers in metal smelters are used for reactive metals such as aluminum and magnesium, operating in molten salt at high temperatures ranging from 750 to 1,000°C. Prebaked carbon anodes in aluminum plants are replaced every 20 to 30 days and are considered continuous consumables. Maintenance of molten salt electrolysis cells requires focused management of thermal balance and lining replacement; the cost of a single lining replacement can reach 3–4 million yuan. Aqueous solution electrolysis cells are used for copper and zinc refining; maintenance of these cells primarily involves the passivation of insoluble anodes and the cleaning of conductive contacts.
Electrolytic cells in electroplating plants come in a wide variety of types, customized according to the metal being plated (copper, nickel, zinc, gold) and the properties of the plating solution (acidic, alkaline, cyanide-based, cyanide-free). The core of electrolytic cell maintenance is plating solution management, which requires daily inspection of the filter’s condition to ensure there are no air or liquid leaks. Soluble anodes (such as zinc and nickel) must be replaced when their consumption reaches 70%. Filter cartridges in the plating solution circulation loop must be replaced weekly (5–10 μm precision). Every six months, the tank must be thoroughly cleaned, the anode bags must be washed, and any damaged anode bags must be replaced. Heating coils should be descaled monthly with 10% citric acid. The voltage drop at busbar connections should be less than 10 mV per connection point; overheating indicates loose contacts or corrosion. Precision electroplating tanks in the electronics manufacturing industry are used for PCB circuit plating and have extremely high requirements for uniformity and purity. Maintenance of these electroplating tanks focuses more on the upkeep of spray systems, cleaning of conductive seats, and control of rectifier ripple voltage (which should be less than 5%). Copper balls and anode bags must be cleaned every 90 days.
Wastewater treatment plants use two-dimensional/three-dimensional electrolytic reactors and unipolar/bipolar electrolytic cells to remove heavy metals or organic compounds through mechanisms such as electrocoagulation and electrooxidation. The most challenging issues in the maintenance of these electrolytic cells are electrode scaling and passivation. Calcium and magnesium ions in the wastewater form carbonate scale on the electrode surfaces, covering the coatings and causing a sharp drop in electrolytic efficiency. Standardized procedures for electrode maintenance include backwashing 1–2 times daily to remove surface deposits and monthly chemical cleaning by soaking in 5% dilute hydrochloric acid or citric acid. The electrode replacement cycle is generally 6–12 months, depending on the material and water quality; it is recommended to use corrosion-resistant materials such as DSA (Dimensionally Stable Anodes). During cleaning, soft-bristled brushes or neutral detergents must be used; the use of strong alkaline solutions or sharp tools to scrape the surface is strictly prohibited to prevent coating peeling. Disinfectant production plants use diaphragm-less electrolyzers to produce sodium hypochlorite disinfectant on-site by electrolysis of dilute brine. The key to maintaining these electrolyzers is acid washing to remove scale—high-hardness feedwater causes calcium and magnesium scale to build up on the electrodes, and regular acid washing is the only way to restore efficiency. The electrolyte temperature must be maintained below 45°C.
The core of hydrogen metallurgy plants, energy storage and peak-shaving facilities, and green ammonia and green methanol synthesis plants lies in generating electricity from renewable energy sources and then producing green hydrogen via large-scale hydrogen-production electrolyzers. The key maintenance points for the alkaline electrolyzers (ALK) and PEM electrolyzers used in these applications are identical to those for the hydrogen-production plants described above. However, the unique challenge in energy transition scenarios lies in the drastic fluctuations in operating conditions—energy storage and peak-shaving require rapid start-up and shutdown of electrolyzers to adapt to the intermittent nature of wind and solar power generation. Enapter recommends limiting electrolyzer start-stop cycles to a maximum of 5 times per day and 1 time per hour to ensure longevity. Under dynamic loads, EIS-based predictive algorithms are considered key tools for intelligent system control and preventive electrolyzer maintenance. A combination of strategies—dynamic current regulation, thermal management, interface engineering, and real-time diagnostics—is essential for ensuring the long-term performance of PEM electrolyzers under intermittent renewable energy operation.
Organic electrosynthesis plants use membrane-less or membrane-equipped electrolyzers to synthesize specific organic compounds, with the choice of membrane use depending on reaction requirements. The challenge in maintaining these electrolyzers lies in the diversity of reaction systems—different organic syntheses have vastly different requirements for electrode materials, membrane selection, and operating parameters. Electrolyzer maintenance must be tailored to the specific synthesis reaction; routine maintenance includes inspecting electrode surfaces (for organic polymer deposits), testing membrane integrity, and analyzing electrolyte composition. Since organic electrosynthesis often involves non-aqueous solvents or specialized electrolytes, sealing materials must exhibit higher chemical resistance than those used in aqueous-based electrolyzers. The replacement intervals for sealing gaskets and piping must be determined based on the specific organic media they come into contact with; there is no standardized industry schedule. It is recommended to enter into a long-term technical service agreement with the electrolyzer manufacturer to ensure the timely supply of critical spare parts (such as specialized electrode coatings and custom diaphragms); this is the most effective management strategy for maintaining this type of electrolyzer.
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