Driven by the global "Dual Carbon" goals, the new energy industry is experiencing explosive growth. Among them, photovoltaics and lithium-ion batteries—two core sectors—are seeing increasingly stringent demands on material performance. Meanwhile, silicone materials, renowned for their exceptional combination of high-temperature resistance, weather durability, insulation properties, and flexibility, are steadily emerging as the "key materials" that underpin the advancement of these two industries. From ensuring the long-term durability of photovoltaic modules to enhancing the safety and energy density of lithium batteries, silicone materials are now deeply integrated into a wide range of applications—and even paving the way for breakthroughs in critical technologies. Today, we’ll take an in-depth look at how silicone materials are being applied across photovoltaic and lithium-ion battery fields, along with the latest innovations driving this transformative trend.
 
1. Photovoltaic Field: Silicone is the silent guardian ensuring "longevity" and boosting efficiency in solar modules.
 
The design life of photovoltaic modules typically needs to reach 25–30 years, and their prolonged exposure to harsh outdoor conditions—such as high temperatures, high humidity, ultraviolet radiation, and windblown sand—places extremely high demands on the materials' weather resistance, insulation properties, and sealing performance. Thanks to their outstanding stability, silicone materials play an irreplaceable role in several key stages of photovoltaic module production, while also driving photovoltaic technology toward even greater efficiency.
 
1. Sealant: The component's first line of defense against water and moisture
 
The sealing between the glass cover plate of photovoltaic modules and the aluminum frame and backsheet is crucial for preventing moisture ingress and avoiding corrosion of the internal circuits. While EVA film, commonly used in the past due to its lower cost, tends to age and yellow over time, negatively impacting the module's light transmittance and lifespan—organic silicone sealants (primarily silicone sealants) perfectly address this critical issue:
 
Outstanding weather resistance: Maintains elasticity across a temperature range of -50°C to 200°C, effectively resisting long-term UV exposure without aging or cracking, ensuring sealing performance for over 25 years.
 
Excellent adhesion: It firmly bonds with a variety of materials, including glass, aluminum, and back sheets (TPT/TPE), and remains securely attached even under conditions of thermal cycling.
 
Reliable insulation: With a breakdown voltage exceeding 20 kV/mm, it effectively safeguards the internal circuitry of components and minimizes the risk of leakage current.
 
Currently, mainstream photovoltaic module manufacturers—such as Jinko and Longi—have widely adopted silicone sealants to replace traditional sealing materials. Particularly in applications with higher sealing performance requirements, like bifacial PV modules and BIPV (Building Integrated Photovoltaics), the penetration rate of silicone sealants has already exceeded 90%.
 
2. Potting Compound: The "Safety Barrier" Between the Inverter and the Junction Box
 
The photovoltaic inverter is the core device that converts direct current into alternating current, housing a large number of electronic components inside. Meanwhile, the junction box is responsible for collecting the current generated by the modules. Both components must withstand the challenges of insulation and heat dissipation in high-temperature, humid environments. Silicone potting compounds provide all-around protection for electronic components through "encapsulating" shielding:
 
Thermally Conductive and Electrically Insulating—A Dual Excellence: Some modified silicone potting compounds achieve a thermal conductivity of 0.8–1.5 W/(m·K), enabling rapid heat dissipation from components during operation (such as IGBT modules) while effectively blocking moisture and dust to prevent short circuits.
 
Flexibility Adaptation: After curing, it retains a certain level of elasticity, helping to relieve thermal expansion and contraction stresses caused by temperature changes in electronic components, thereby reducing failures such as solder joint detachment and circuit breakage.
 
For example, in centralized inverters, silicone potting compounds have become the standard protective material for critical components such as IGBT modules and capacitors, reducing the inverter’s failure rate by more than 30% and extending its service life to over 15 years.
 
3. Technological Breakthrough: Enabling the Mass Production of Highly Efficient Photovoltaic Cells
 
As photovoltaic technology advances toward high-efficiency battery approaches such as TOPCon (Tunnel Oxide Passivated Contact) and HJT (Heterojunction), new demands are placed on the refined performance of materials—and consequently, silicon-based materials have also achieved significant technological breakthroughs.
 
Low-VOC silicone coatings: In the preparation of transparent conductive oxide (TCO) films for HJT cells, traditional coatings tend to release volatile impurities that can compromise the battery's passivation performance. In contrast, low-VOC silicone coatings significantly reduce impurity emissions, boosting the conversion efficiency of HJT cells by 0.3 to 0.5 percentage points.
 
High-temperature-resistant silicone film: The fabrication of TOPCon cells requires a high-temperature doping process (above 300°C), which traditional EVA films struggle to withstand. In contrast, the high-temperature-resistant silicone film remains stable even at 350°C and boasts a light transmittance rate exceeding 94%, making it a critical complementary material for TOPCon modules.
 
II. Lithium Battery Field: Organosilicon Ensures "Safety" and "High Capacity" for Batteries
 
Lithium batteries are the core power source for new-energy vehicles and energy storage systems, and their safety—specifically, prevention of thermal runaway—and energy density—determining range—are at the heart of industry competition. By innovatively integrating silicone materials into components such as electrodes, electrolytes, and battery casings, these materials not only enhance battery safety performance but also help push energy density to new heights, making them a key driver in upgrading the lithium-battery industry.
 
1. Electrode Modification: Enhancing Capacity and Cycle Life
 
The performance of lithium battery electrodes (cathode and anode) directly determines the battery's energy density and cycle stability. Traditional electrode materials—such as ternary cathodes and graphite anodes—suffer from issues like poor conductivity and significant volume expansion (e.g., in silicon-based anodes). However, organosilicon modifiers can effectively address these drawbacks:
 
Positive electrode surface coating: Coating a nano-sized organosilicon film on the surface of ternary cathode materials (such as NCM811) can reduce side reactions between the cathode and the electrolyte, suppress the dissolution of transition metal ions, and extend the battery's cycle life by more than 50%—increasing it from 1,000 cycles to over 1,500 cycles—while also lowering the risk of thermal runaway.
 
Silicon-based anode bonding: Silicon-based anodes boast a theoretical capacity more than 10 times that of graphite anodes, yet they experience a volumetric expansion rate as high as 300% during charge-discharge cycles, making the electrodes prone to pulverization and detachment. By employing organic silicon-based elastic adhesives—such as silane-modified resins—these volume expansion stresses can be buffered through elastic deformation, boosting the initial charge-discharge efficiency of silicon-based anodes to over 90%. Moreover, after 500 cycles, the anodes maintain a capacity retention rate exceeding 80%.
 
Currently, leading lithium-ion battery companies such as CATL and BYD have already adopted silicon-modified electrode technology in high-capacity batteries, driving the energy density of power batteries from 200 Wh/kg to over 300 Wh/kg—and beyond—to meet the demand for new-energy vehicles with a range of more than 600 kilometers.
 
2. Electrolyte additives: Inhibit thermal runaway and enhance safety
 
The electrolyte serves as the "bridge" for ion transport in lithium batteries, but traditional electrolytes (carbonate-based systems) tend to decompose easily at high temperatures, generating flammable gases such as CO and CH4—key triggers for thermal runaway. The addition of organosilicon electrolyte additives (such as siloxanes and silanes) can fundamentally enhance the safety of the electrolyte.
 
High-Temperature Stability: The molecular structure of the silicone additive contains Si-O bonds, which have a bond energy as high as 452 kJ/mol—significantly greater than the 347 kJ/mol found in C-C bonds. As a result, these bonds remain stable even above 150°C, helping to minimize gas generation from the electrolyte at elevated temperatures.
 
Forming a Stable SEI Film: The silicone additive preferentially decomposes on the electrode surface, creating a dense and stable solid electrolyte interphase (SEI) film that prevents further reactions between the electrolyte and the electrode, while simultaneously enhancing ionic conductivity.
 
Experimental data show that adding a 5% silicone additive to the electrolyte can raise the thermal runaway temperature of lithium batteries from 180°C to over 230°C, significantly reducing the battery's risk of ignition by more than 60% in abuse tests such as nail penetration and compression.
 
3. Battery Case Sealing and Thermal Management: Optimized for Fast Charging and High-Power Applications
 
With the growing adoption of fast-charging technologies for new-energy vehicles—such as the 800V high-voltage platform—lithium batteries generate significant heat during rapid charging. Meanwhile, the sealing performance of the battery casing directly affects the risk of electrolyte leakage. In this scenario, silicone materials play a dual role: "thermal management" and "sealing."
 
Silicone thermal pads: Placed between the battery module and the housing, these pads offer a thermal conductivity of up to 2–5 W/(m·K), efficiently dissipating the heat generated during fast charging. This keeps the battery temperature below 45°C, preventing high temperatures from compromising battery performance.
 
Silicone sealing rings: Designed for interface sealing in battery housings, these rings can withstand temperature fluctuations ranging from -40°C to 120°C and are highly resistant to electrolyte corrosion (unlike conventional rubber seals, which tend to swell when exposed to electrolytes), ensuring no electrolyte leakage throughout the battery's lifespan.
 
For instance, automakers like XPeng and Li Auto have fully adopted silicone-based thermal pads and seals in their 800V high-voltage models, reducing fast-charging time from over 1 hour to within 30 minutes (when charging up to 80% capacity), while also ensuring battery safety.
 
III. Technical Breakthrough Directions for Organosilicon Materials in the New Energy Field
 
As photovoltaic and lithium-ion technologies continue to advance, silicone materials are also undergoing sustained innovation, primarily focusing on three major technological breakthroughs that further unlock their application potential:
 
1. Low-loss, High-Thermal-Conductivity Modification Technology
 
In the photovoltaic field: Addressing the trend toward higher frequencies in PV inverters, we have developed a silicone potting compound with low dielectric loss (tanδ < 0.001), which minimizes energy dissipation during high-frequency signal transmission and enhances inverter efficiency.
 
In the lithium-ion battery field: Develop high-thermal-conductivity (thermal conductivity > 5 W/(m·K)) silicone-based composite materials by incorporating thermally conductive fillers such as graphene and aluminum nitride, further enhancing the battery's cooling performance to support future 4C and 5C ultra-fast charging technologies.
 
2. Eco-friendly and Low-Cost Process Innovation
 
Bio-based silicone: Utilizing plant oils—such as castor oil—to replace traditional petrochemical feedstocks in the production of silicone monomers, thereby reducing reliance on fossil resources while also cutting carbon emissions during the manufacturing process (by more than 20% compared to conventional methods).
 
Integrated Molding Process: Developing an integrated molding technology that combines silicone sealants with adhesive films, streamlining the production processes for photovoltaic modules and lithium batteries, and reducing manufacturing costs for companies—for instance, encapsulation costs for photovoltaic modules could be lowered by up to 15%.
 
3. Functional Integration Design
 
Photovoltaic + BIPV Applications: Develop colorized silicone materials that combine sealing, bonding, and decorative functions, perfectly matching the aesthetic requirements of BIPV buildings while maintaining exceptional weather resistance.
 
The trend toward solid-state lithium batteries: To advance solid-state lithium battery technology, researchers are developing silicon-based solid electrolytes that combine high ionic conductivity (>10⁻³ S/cm) with exceptional flexibility, addressing the major drawbacks of traditional solid electrolytes—such as oxides—namely their brittleness and high interfacial impedance.
 
IV. Future Outlook: Silicon-based materials will be deeply integrated into the upgrading of the new energy industry.
 
As the global new energy industry accelerates its expansion—projecting that by 2030, global photovoltaic installations will surpass 1 TW, and lithium-battery demand will exceed 2 TWh—the market demand for silicone materials is also set to continue growing. According to industry data, the global market size for silicone materials in the new energy sector is expected to exceed 20 billion yuan by 2025, with an annual compound growth rate consistently remaining above 15%.
 
From a technical perspective, silicone materials will no longer be limited to their "supportive protective" role—they are shifting toward becoming "performance-enabling" assets. For instance, in the photovoltaic sector, they are helping enhance the stability of perovskite solar cells, while in the lithium-ion battery field, they are accelerating the mass production and commercialization of solid-state batteries. Meanwhile, as environmental regulations become increasingly stringent, eco-friendly, low-VOC, and recyclable silicone materials will emerge as the industry standard, further driving the "full-lifecycle decarbonization" of the new energy sector.
 
It can be said that the integration of silicone materials with the photovoltaic and lithium-ion battery industries represents both a "precise match" to the inherent properties of these materials—and an "inevitable choice" for advancing new energy technologies. Looking ahead, as these two sectors become more deeply intertwined, we’ll witness the emergence of next-generation energy products that are not only more efficient and safer but also more environmentally friendly, seamlessly entering our daily lives and providing robust material support for achieving global "dual-carbon" goals.