Battery-Supercapacitor Hybrids

Detailed overview of innovation with sample startups and prominent university research

What it is

Battery-supercapacitor hybrids combine the high energy density of batteries with the high power density and fast charge-discharge capabilities of supercapacitors. This hybrid approach aims to create energy storage systems with improved performance characteristics, such as longer cycle life, faster charging times, and higher power output.

Impact on climate action

Battery-Supercapacitor Hybrids in Battery Storage enhance climate action by improving energy storage efficiency and grid stability. By combining the high energy density of batteries with the rapid charge and discharge capabilities of supercapacitors, these innovations enable more reliable renewable energy integration, reduce reliance on fossil fuels, and mitigate carbon emissions.


  • Batteries: Batteries store energy through chemical reactions, offering high energy density but limited power output and slower charge-discharge rates.
  • Supercapacitors: Supercapacitors store energy electrostatically, by accumulating ions at the interface between an electrode and an electrolyte. They offer high power density and fast charge-discharge capabilities but lower energy density compared to batteries.
  • Hybrid System Design: Battery-supercapacitor hybrids combine these two technologies in various configurations to leverage their complementary strengths. This can involve connecting batteries and supercapacitors in parallel, series, or a combination of both, depending on the desired performance characteristics.
  • Energy Management System (EMS): An EMS is crucial for managing the energy flows between the battery and supercapacitor, ensuring optimal performance and efficiency.

TRL : 6-7

Prominent Innovation themes

  • Advanced Battery Chemistries: Innovations in battery chemistries, such as lithium-ion and sodium-ion batteries, are improving energy density and cycle life, making them more suitable for hybrid systems.
  • High-Performance Supercapacitors: Advancements in supercapacitor technology, such as the use of new electrode materials and electrolytes, are increasing power density and energy density, making them more effective in hybrid systems.
  • Hybrid System Optimization: Researchers and startups are developing optimization algorithms and control strategies to manage energy flows between the battery and supercapacitor, maximizing performance and efficiency.
  • Integrated Hybrid Systems: Companies are developing integrated hybrid energy storage systems that combine batteries and supercapacitors into a single, optimized package.

Other Innovation Subthemes

  • Hybrid System Configuration Optimization
  • Electrode Material Innovations for Supercapacitors
  • Battery-Supercapacitor Integration Strategies
  • Advanced Control Algorithms for Hybrid Systems
  • Applications in Electric Vehicle Charging Infrastructure
  • Supercapacitor Electrolyte Innovations
  • Hybrid System Performance Modeling
  • Battery-Supercapacitor Integration in Portable Electronics
  • Grid-Scale Energy Storage Applications
  • Thermal Management Solutions for Hybrid Systems
  • Battery-Supercapacitor Integration in Renewable Energy Systems
  • Supercapacitor Electrode Architecture Innovations
  • Hybrid System Reliability and Durability Enhancements
  • Battery-Supercapacitor Integration in Microgrids
  • Supercapacitor Energy Density Enhancements
  • Battery-Supercapacitor Integration in Aerospace Applications
  • Supercapacitor Voltage Stability Improvements
  • Battery-Supercapacitor Integration in Smart Grids

Sample Global Startups and Companies

  1. Skeleton Technologies:
    • Technology Enhancement: Skeleton Technologies is a leading manufacturer of ultracapacitors, also known as supercapacitors, and energy storage systems. Their hybrid solutions combine the high energy density of batteries with the high power density and rapid charge-discharge capabilities of supercapacitors. By integrating both technologies, Skeleton Technologies aims to optimize energy storage performance for applications requiring high power bursts and frequent cycling.
    • Uniqueness of the Startup: Skeleton Technologies stands out for its expertise in ultracapacitor technology and its focus on developing hybrid energy storage solutions for various industries, including automotive, transportation, and renewable energy. Their patented materials and manufacturing processes enable the production of ultracapacitors with industry-leading performance and reliability.
    • End-User Segments Addressing: Skeleton Technologies serves customers in sectors where high power density, fast charging, and long cycle life are critical requirements. Their battery-supercapacitor hybrids are deployed in applications such as regenerative braking systems, grid stabilization, industrial machinery, and hybrid electric vehicles (HEVs), offering enhanced energy efficiency and performance.
  2. Maxwell Technologies (acquired by Tesla, Inc.):
    • Technology Enhancement: Maxwell Technologies was a pioneer in ultracapacitor technology and energy storage solutions. Their hybrid systems combined lithium-ion batteries with ultracapacitors to provide improved power performance, energy efficiency, and lifespan. By integrating both technologies, Maxwell Technologies aimed to address the limitations of batteries alone, such as high-power demands and cycle life degradation.
    • Uniqueness of the Startup: Maxwell Technologies was known for its innovative approach to energy storage and its development of hybrid systems that leverage the strengths of both batteries and ultracapacitors. Their solutions offered benefits such as faster charging, longer cycle life, and enhanced reliability, making them suitable for applications requiring high power and frequent cycling.
    • End-User Segments Addressing: Maxwell Technologies served customers in industries such as automotive, transportation, renewable energy, and grid infrastructure. Their hybrid energy storage systems were deployed in applications such as hybrid and electric vehicles, renewable energy integration, and grid stabilization, providing improved performance and efficiency.
  3. EEStor Corporation:
    • Technology Enhancement: EEStor Corporation focused on developing high-energy-density capacitors, also known as Electrical Energy Storage Units (EESUs), based on a proprietary ceramic technology. While there were claims and ambitions regarding the potential of their technology in electric vehicles and grid storage, the commercialization and practical application of their products faced significant challenges and skepticism.
    • Uniqueness of the Startup: EEStor Corporation gained attention for its ambitious goals of developing ultracapacitor-like energy storage devices with exceptional energy density and fast charging capabilities. However, the company faced technical and commercialization hurdles that limited its progress in bringing products to market.
    • End-User Segments Addressing: EEStor Corporation aimed to serve industries and applications requiring high-energy-density storage solutions, such as electric vehicles, renewable energy storage, and grid-scale energy storage. However, due to challenges in product development and commercialization, the practical deployment of their technology remained limited.

Sample Research At Top-Tier Universities

  1. Massachusetts Institute of Technology (MIT):
    • Research Focus: MIT is actively involved in research on Battery-Supercapacitor Hybrids, exploring novel hybrid energy storage systems that combine the high energy density of batteries with the high power density and rapid charge/discharge capabilities of supercapacitors.
    • Uniqueness: Their research involves the development of advanced electrode materials, electrolytes, and device architectures to optimize the performance, cycle life, and safety of battery-supercapacitor hybrid systems. They investigate innovative fabrication techniques, such as nanostructuring, surface functionalization, and hybridization strategies, to enhance the electrochemical properties and energy storage mechanisms of hybrid energy storage devices.
    • End-use Applications: The outcomes of their work have applications in electric vehicles, grid-scale energy storage, portable electronics, and renewable energy integration. By combining the complementary advantages of batteries and supercapacitors, MIT’s research aims to address the performance limitations and cost barriers associated with conventional energy storage technologies, enabling more efficient, reliable, and sustainable energy storage solutions.
  2. Stanford University:
    • Research Focus: Stanford University conducts pioneering research on Battery-Supercapacitor Hybrids, leveraging its expertise in materials science, electrochemistry, and device engineering to develop next-generation hybrid energy storage systems with enhanced performance and functionality.
    • Uniqueness: Their research encompasses the design and synthesis of hybrid electrode materials, including transition metal oxides, carbon-based nanomaterials, and conducting polymers, tailored to meet the specific requirements of battery-supercapacitor hybrid architectures. They explore advanced manufacturing techniques, such as 3D printing, electrodeposition, and chemical vapor deposition, to fabricate hierarchical nanostructures and multifunctional interfaces for improved energy storage and electrochemical stability.
    • End-use Applications: The outcomes of their work find applications in portable electronics, wearable devices, renewable energy storage, and aerospace applications. By pushing the boundaries of energy storage technology, Stanford’s research aims to enable new functionalities, longer cycle life, and faster charging/discharging rates for a wide range of emerging energy storage applications.
  3. University of California, Los Angeles (UCLA):
    • Research Focus: UCLA is engaged in innovative research on Battery-Supercapacitor Hybrids, focusing on developing hybrid energy storage systems capable of delivering high energy density, high power density, and long cycle life for diverse applications.
    • Uniqueness: Their research involves exploring novel electrode materials, electrolyte formulations, and device architectures to enhance the electrochemical performance, stability, and safety of battery-supercapacitor hybrid systems. They investigate innovative synthesis methods, such as sol-gel processing, atomic layer deposition, and electrode functionalization, to tailor the physicochemical properties and ion transport kinetics of hybrid energy storage materials.
    • End-use Applications: The outcomes of their work have applications in electric vehicles, renewable energy integration, consumer electronics, and grid-scale energy storage. By advancing the state-of-the-art in battery-supercapacitor hybrid technology, UCLA’s research contributes to overcoming the performance limitations and scalability challenges of current energy storage solutions, paving the way for more efficient, compact, and cost-effective energy storage systems.

commercial_img Commercial Implementation

Battery-supercapacitor hybrids are being implemented in various applications, including:

  • Electric Vehicles: Hybrid energy storage systems can provide both high power for acceleration and high energy density for extended range in electric vehicles.
  • Grid-Scale Energy Storage: Hybrid systems can provide grid services, such as frequency regulation and peak shaving, while also offering long-duration energy storage capabilities.
  • Industrial Equipment: Hybrid systems can provide power for heavy-duty equipment, such as forklifts and cranes, while also offering energy storage for backup power or peak shaving.