Non Conductive Lubricants for Electric Vehicles
Electric vehicle (EV) lubricants operate under fundamentally different constraints than their conventional counterparts. Unlike traditional combustion engines, EV powertrains generate electrical potentials of 400-800V, creating environments where standard lubricants with electrical conductivity above 1000 nS/m risk enabling parasitic current pathways. Testing reveals that exposure to these conditions accelerates oxidative degradation, with some formulations losing 40-50% of their base viscosity after just 500 hours of operation under simulated drive cycles.
The engineering challenge lies in balancing electrical insulation properties with the mechanical protection required for high-torque EV transmissions while simultaneously maintaining compatibility with copper windings and sensitive electronic components.
This page brings together solutions from recent research—including formulations utilizing phosphorylated bis-succinimide dispersants, high-molecular-weight succinimide systems post-treated with phosphorus-boron compounds, polyalkylene glycol/poly-alpha-olefin/ester blends, and triazole corrosion inhibitors combined with amine-sulfur antiwear additives. These and other approaches demonstrate how lubricant chemistry is being reconfigured to address the particular needs of electric propulsion systems while maintaining the required thermal management capabilities.
1. Lubricating Composition with Phosphorylated Bis-Succinimide Dispersant and High Electrical Resistivity
CHEVRON ORONITE COMPANY LLC, 2025
Lubricating composition for electric vehicles with improved electrical resistivity and antiwear properties, comprising a major amount of lubricating oil and about 1.0-5.0 wt.% of a phosphorylated dispersant derived from a bis-succinimide and dialkyl dithiophosphoric acid, wherein the composition is substantially free of zinc and exhibits a volume resistivity of 10^8 ohm-cm or greater at 120°C.
2. ADDITIVE AND BASE OIL TRENDS IN EV APPLICATIONS
Raj Shah, M.B. Das, Humaun Kabir - ASME International, 2025
Abstract Electric vehicle (EV) technology has matured over time, improving in some performance areas against traditional internal combustion engine (ICE) vehicles. Despite advancement, there is considerable opportunities for further improvements, particularly in the broader field of lubrication, including areas like grease. As in any mechanical system, greases and lubricants play a significant role in the component life of EV power plants and drivetrains. Moreover, they can significantly contribute to vehicle efficiency, energy savings, and overall driving experience. Since the lubricants in EVs work under harsh thermal and electrical environments, designing an ideal high performance and stable lubricant can be challenging. This paper evaluates the industry's progress on EV lubrication including analyzing existing lithium-based lubricants and spotlighting advanced material additives such as graphene, boron nitride, or cutting-edge ionic liquids. It also discusses optimizing base stock selection, with a focus on Polyalphaolefin (PAO) molecules and designing various additives to enhanc... Read More
3. Lubricating Oil Composition with Soluble Sulfur-Containing Additive for Electric Vehicles
CHEVRON ORONITE COMPANY LLC, 2025
Lubricating oil composition for electric vehicles, comprising a major amount of lubricating oil, a phosphorus-containing additive, and a sulfur-containing additive selected from thiadiazole, dithiadiazole, dimercaptodithiadiazole, and derivatives thereof, wherein the sulfur-containing additive is soluble in the lubricating oil without the need for a dispersant additive.
4. Lubricating Oil Compositions with Anti-Fatigue Additive and Sulfonate Detergent
CHEVRON ORONITE CO, 2025
Lubricating oil compositions with enhanced fatigue protection, particularly suitable for functional fluids and electric vehicle applications, comprising 0.001-1.5% anti-fatigue additive and sulfonate detergent, with reduced levels of sulfur-containing compounds, such as metal sulfurized phenates, and optionally glycerol, which imparts improved fatigue performance without compromising anti-wear properties.
5. Electric Vehicle Transmission Fluid with Oxidation Inhibitors and Low Conductivity for Compatibility with Yellow Metals and Electrical Components
VGP IPCO LLC, 2024
Electric vehicle transmission fluid formulation designed to meet the unique demands of EV drive systems, providing improved lubrication, wear protection, and compatibility with yellow metals and electrical components. The formulation includes oxidation inhibitors, anti-wear additives, and copper corrosion protection, while maintaining low electrical conductivity and thermal stability. The fluid is engineered to withstand extreme power and torque fluctuations, and is designed to be compatible with a wide range of EV transmission materials.
6. Triboelectric Performance of Ionic Liquid, Synthetic, and Vegetable Oil-Based Polytetrafluoroethylene (PTFE) Greases
Nur Aisya Affrina Mohamed Ariffin, Chiew Tin Lee, Arunkumar Thirugnanasambandam - MDPI AG, 2024
Within electrical contacts, poor electrical conductivity of lubricants can lead to triboelectric charging, causing electrostatic currents and thermal effects, which accelerate lubrication failure. This study aimed to address these challenges by producing and testing three greases with different base oils: ionic liquid ([Oley][Oleic]), synthetic oil (PAO4), and vegetable oil-based synthetic ester (trimethylolpropane oleate). Each grease was prepared with polytetrafluoroethylene powder as the thickener. The greases were tested using a custom-made tribometer, integrated with a grounded electrical current system, with friction tests conducted with up to a 2 A electrical current flow at a constant voltage supply of 4.5 V. Under triboelectric friction testing, [Oley][Oleic] grease outperformed a commercial perfluoropolyether grease by 27.7% in friction and 16.3% in wear. This grease also showed better performance than formulated lithium grease with extreme pressure additives. The study demonstrates that greases with low interfacial resistance can retain their lubrication capacity under tri... Read More
7. Lubricant Composition with Triazole Corrosion Inhibitors and Amine-Sulfur Anti-Wear Additives
TOTALENERGIES ONETECH, 2024
Lubricant composition for electric vehicle propulsion systems that improves antiwear and anticorrosion properties by combining triazole corrosion inhibitors with amine- and sulfur-based antiwear additives. The triazole compounds like tolyltriazole prevent corrosion of metal components while the amine-sulfur additives like dimercaptothiadiazoles reduce wear. This combination provides simultaneous wear and corrosion protection for electric vehicle motors, bearings, and transmissions.
8. Lubricating Fluid for Electric Motors with Succinimide Dispersant and Phosphorus-Boron Post-Treatment
AFTON CHEMICAL CORP, 2024
A lubricating fluid for electric motor systems in hybrid and electric vehicles, comprising a base oil of lubricating viscosity, a high molecular weight succinimide dispersant, an amine salt of a phosphoric acid ester, an ashless dialkyl dithiophosphate, and a sulfur-providing additive. The fluid has a kinematic viscosity of 4.5 cSt or less, 150-250 ppm total phosphorus, and an electrical conductivity of 37 nS/m or less. The succinimide dispersant is derived from a polyisobutylene with a number average molecular weight of 2000 or greater, and is post-treated with a phosphorus and boron containing compound.
9. Lubricant Composition with Polyalkylene Glycol, Poly-alpha-olefin, and Ester Blend Including Sulfur-Based Extreme Pressure Agent
IDEMITSU KOSAN CO LTD, 2024
A lubricant composition for electric and hybrid vehicle motors, comprising a base oil blend of polyalkylene glycol (PAG), poly-alpha-olefin (PAO), and ester, with an additive package including a sulfur-based extreme pressure agent. The PAG provides thermal stability and low viscosity, while the PAO and ester enhance solubility and compatibility with the extreme pressure agent. The composition is optimized for electric motor applications, avoiding additives typically used in conventional lubricants that can degrade performance.
10. Lubricating Oil Composition with High Transmittance and Specific Viscosity for Electric Vehicle Thermal Management Systems
IDEMITSU KOSAN CO, 2024
Lubricating oil composition for electric vehicle systems that circulates through a circuit connecting a battery, motor, and transaxle, providing thermal management and insulation properties. The composition has a high transmittance of 90% or more and a kinetic viscosity of 1.0-2.2 mm2/s at 100°C. The composition is used in a circulation system that controls temperatures of the battery, motor, and transaxle through a network of paths and valves.
11. Electric Potential Controlled Ionic Lubrication
Zhongnan Wang, Hui Guo, Sudesh Singh - MDPI AG, 2024
Electric potential controlled lubrication, also known as triboelectrochemistry or electrotunable tribology, is an emerging field to regulate the friction, wear, and lubrication performance under charge distribution on the solidliquid interfaces through an applied electric potential, allowing to achieve superlubrication. Electric potential controlled lubrication is of great significance for smart tunable lubrication, micro-electro-mechanical systems (MEMS), and key components in high-end mechanical equipment such as gears and bearings, etc. However, there needs to be a more theoretical understanding of the electric potential controlled lubrication between micro- and macro-scale conditions. For example, the synergistic contribution of the adsorption/desorption process and the electrochemical reaction process has not been well understood, and there exists a significant gap between the theoretical research and applications of electric potential controlled lubrication. Here, we provide an overview of this emerging field, from introducing its theoretical background to the advantages and c... Read More
12. Lubricating Oil Composition with Mineral Base Oil and Fluorine Compound for Electric Vehicle Cooling Systems
IDEMITSU KOSAN CO LTD, 2024
A lubricating oil composition for electric vehicle cooling systems, comprising a base oil and a fluorine compound, where the base oil is a mineral oil with a 40°C kinematic viscosity of 1-25 mm²/s, and the fluorine compound content is 3-30% by weight. The composition provides both lubricity and cooling performance, enabling efficient heat management in electric vehicle systems.
13. Lubricating Oil Composition with Extreme Pressure Agent and Nitrogen-Containing Ashless Dispersant
ENEOS CORP, 2024
Lubricating oil composition for electric vehicles comprising a lubricating oil base oil, an extreme pressure agent, and a nitrogen-containing ashless dispersant, suitable for lubricating both electric motors and gear mechanisms in integrated electric vehicle powertrains.
14. Lubrication subjected to effects of electric and magnetic fields: recent research progress and a generalized MEMT-field Reynolds equation
Xiaoman Wang, Q. Jane Wang, Ning Ren - Frontiers Media SA, 2024
Electric and magnetic fields have been used in various ways to enhance the performance of lubrication systems. The presence of these fields can significantly change the properties of lubricants. The rapid adoption of electric vehicles (EVs) has presented new lubrication-related challenges due to the presence of electric current. There is an urgent need for an in-depth study of lubrication systems subjected to such fields. This paper highlights recent research works on several key areas of lubrication involving electric or magnetic fields, which are:1) electric double layer in lubrication, 2) electrorheological fluids, 3) magnetorheological fluids, 4) ferrofluids, and 5) typical fluids used in the current EVs and typical surface failures of bearing components in EVs. Commonly used lubricants in each area are reviewed; lubrication mechanisms and related mathematical models are summarized; methods for and results from numerical analyses and experimental explorations are discussed; and common features of lubrications in different fields are explored. Based on the current research progres... Read More
15. Lubricating Fluid Composition with Borated Succinimide, 2,5-Alkyl-Thiadiazole, and Phosphorus Additive for Electric Drives
VOLKSWAGEN AG, 2024
A lubricating fluid composition for electric drives that prevents corrosion of electrical components while maintaining high efficiency in transmissions. The composition comprises 10-88% by weight of a low-viscosity synthetic oil, 0.1-5% by weight of a borated succinimide dispersant, 0.1-5% by weight of a 2,5-alkyl-thiadiazole compound, and 0.1-5% by weight of a phosphorus-containing additive. The composition has a dynamic viscosity of 0.8-4.0 mm2/s at 100°C and is suitable for use in electric motors, transmissions, and battery-operated vehicles.
16. Thermal and electrical properties of electric vehicle fluids
Kailash Arole, Micah J. Green, Hong Liang - Elsevier, 2024
Electric vehicles (EVs) have gained increased attention in recent years owing to their excellent performance and emission of less hazardous products to the surroundings. The varied design of EVs compared to the internal combustion engine vehicles has created new requirements in lubricants and fluids for their operation. The increasing electrification of vehicle drivetrains has led to lubricants being in contact with more electrical components, such as motors, sensors, battery modules, and power electronics. This has led to different operating conditions, such as being subjected to an electric field, higher rpm, and higher thermal stress, affecting the electrical properties of lubricants, especially for electrified transmission fluid. The electrical properties of lubricants play a vital role in preventing corona discharge and arc absorbance, which can cause premature failure and electromagnetic interference problems in motors, leading to bearing instability, excessive vibrations, and noise. Understanding the interactions of lubricants with the electric field is crucial for optimizing ... Read More
17. Glycerol-based lubricants for electric vehicles
Yijun Shi, Marcus Björling, Roland Larsson - Elsevier, 2024
To increase the driving range of electric vehicles (EVs) and to make them less dependent on fossil-based technology, it is important to switch to new types of lubricants with low friction and renewable origin. During the past couple of decades, researchers found that glycerol, which is biodegradable and nontoxic, can provide superlubricity even under high contact pressure with rough surfaces. Glycerol can also be used as a coolant for EVs to increase the efficiency of the electric motors. This chapter gives a summary of the tribological performance of different contacts, i.e., steel-steel, steel-diamond-like carbon (DLC), DLC-DLC, steel-self-lubricating materials, and steel-ceramic, which are lubricated by glycerol.
18. Lubrication of bearings under electrical conditions
Guoxin Xie, Jianbin Luo - Elsevier, 2024
The understanding of the lubrication properties under electrical conditions, in order to achieve the suppression of electrical damage and even use the electrical environment to promote lubrication, is highly relevant to the bearings used in electric cars. In this chapter, important research progress on lubrication as well as the premature failure of bearings under electrical conditions in the past decades will be briefly reviewed. The basic research on dry friction under electrical conditions and then the molecular adsorption and orientation at the lubricated interface under electrical conditions will be discussed. Subsequently, microbubble behaviors in thin lubrication films under electrical conditions will be introduced. The electrodamage in bearings under electrical conditions and the protection technology are discussed in the final part.
19. Dielectric Strength of Electric Vehicle Fluids (Lubricants and Coolants) at Usual Operating Temperatures
Julio A. Cao-Romero-Gallegos, Cesar David Resendiz-Calderon, Irving Cazarez-Ramírez - IEEE, 2023
The development of suitable fluids, including lubricants or coolants, for electric vehicles (EVs) requires large efforts on their formulation, characterization, and performance testing. An important property for these fluids is dielectric strength or breakdown voltage (BDV), which is expected to be as high as possible at wide temperature range. Short circuits and bearing currents are highly undesirable phenomena which are known to cause inefficiencies and potential failure or wear of electromechanical hardware if BDV magnitude is not adequate. In modern EVs, the typical fluids comprise lubricants (for bearings and gears in the driveline) such as automatic transmission fluids (ATFs) and low-viscosity gear oils, and coolants (for thermal management in the battery pack and power electronics), namely, ethylene-glycols and dielectric oils. Although these fluids are reported to have acceptable BDV at room temperature (according to ASTM D877 and/or D1816 standard methods) for electric equipment, BDV is likely to be altered when temperature changes occur. The information of BDV at room (20-3... Read More
20. Lubricating Grease Composition with Tailored Oil Viscosity and Frictional Properties for Electric Vehicles
VGP IPCO LLC, 2023
High-efficiency lubricating grease for electric vehicles that reduces energy consumption by optimizing oil viscosity and frictional properties. The grease formulation includes a thickener, lubricating oil, surface-active ester, and additives such as friction reducers and anti-wear agents. The composition can be tailored to achieve specific NLGI consistency grades and viscosity classifications for various EV components.
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