Tesla Buys Maxwell and Spotlights the Future Potential of EDLC Supercapacitors

Source: TTI Market Eye article

by Dennis Zogbi, Paumanok Inc.

Supercapacitors have grabbed the spotlight in the capacitor world during the month of February 2019 following the announcement that Tesla Motors had acquired Maxwell Technologies, a key global vendor of electric double layer carbon (EDLC) supercapacitors. Maxwell Technologies is a global market leader in the field, and based on Paumanok estimates, the world’s largest vendor of carbon dielectric capacitors. Their success in the market is due to their years of experience, economies of scale to manufacture complex electrochemical capacitors, and technical experience in dielectric packaging for that special design engineer who needs capacitance in the farad range.

What the Purchase of Maxwell by Tesla Means for the Industry

The Auto Angle:
In February 2019 the purchase of Maxwell by Tesla placed a spotlight on the markets, technologies and opportunities central to the global electric double layer carbon industry.  For years the technology sought a champion, a large automotive company that would produce a major car platform that employed double layer carbon supercapacitors in series and in parallel to create a high voltage source of burst energy that could load level the electric vehicle, or hybrid electric vehicle during peak power requirements (such as driving up a hill).

Before this, in the automotive space, Nissan was the most active automotive company, advancing and perfecting the use of supercapacitors for tailgate assist on their large commercial trucks throughout Japan. There was also a prototype built in Germany of a sports utility vehicle that employed 100 capacitors in the back wheel-wells of the car in order to provide burst power.  However, to date, no major transportation company, (outside the global bus industry), has attempted to use supercapacitors in any major automotive platform, until now.

The Space Communications Angle:
A few of my scientist/engineering customers who called to talk about the Tesla and Maxwell announcement were in the space electronics business. They were of the school of thought that Tesla was also interested in Maxwell for the use of their supercapacitors in space based applications for pulsed communications-data transmission, which would also be a logical reason why Tesla saw a good fit and acquired Maxwell (with pulsed data transmission for points of demarcation for the Internet of Things looking very exciting as a future emerging market in conjunction with the roll-out 5G infrastructure.  It is not necessarily an EDLC capacitor solution as we expect solid competition from other types of electrochemical capacitors in this very lucrative emerging market).

What’s more, strictly from a technological point of view; is that the acquisition of Maxwell by an auto company like Tesla Motors is an endorsement, an acceptance of double layer carbon capacitor technology by a major automotive platform.

Here is a look at the historical development of supercapacitors

Historical Development of Supercapacitor Technology

The First Carbon Capacitors: 1972:
The first “supercapacitors” were defined as such because of their ability to generate capacitance values measured in farads (instead of microfarads and picofarads, which are the quantity of measurement by which all other capacitor products are sold). The first “explorers” in this market were GE and Sohio (in 1972, and this can be traced back using patent searches).  However, the first companies to commercialize the technology and mass-produce it were Philips of Holland and Panasonic of Japan.

Of course, Panasonic and their Gold Cap product line are still active in the business and maintain considerable market share today.  Philips, however, exited the passive component industry years ago. Yet, Panasonic still maintains breadth and depth of EDLC product line that rivals almost all competitors.  Panasonic’s recent announcement of withdrawing from the coin cell EDLC business may in fact create a shortage environment given Panasonic’s significant share and economies of scale in the space).

Expanding The Carbon Capacitor Market: 1973-1998:
Between 1973 and 1990 many companies in Japan (Tokin, Elna) and Russia (Econd) began experimenting and producing a variety of small can and large supercapacitor cells whose similarities were that they had a high-power density (charge/discharge rate) expressed as watts per kilogram, and a high level of energy density (for burst power).

Also, the “super” capacitors had capacitance values expressed well into the Farad range and had low voltage per cell, usually between 2.5 and 2.7 Vdc.  By 1998 there were four companies that defined the market for supercapacitors, and these were Panasonic, NEC-Tokin, Elna Capacitor, and Maxwell Technologies.

The Participants In EDLC Capacitors Multiply: 1999-2019:
Between 1999 and 2019 the number of manufacturers of “supercapacitors” blossomed to 41 companies globally. This was the direct result of the ease of market entry made even smoother by the concerted effort of key raw material vendors supplying “turn-key” anode and cathode systems to the industry.

During this time-period, major manufacturers of aluminum electrolytic capacitors (Nippon Chemi-Con, Nichicon, Rubycon) and power film capacitors (Shizuki) in Japan also entered the market and quickly assumed market leadership positions because of their access to the existing customer base in power conversion. Some of the early supercapacitor vendors (only a few) were involved in the battery market beforehand, but an even larger number of manufacturers were standalone vendors who had only plans on producing just supercapacitors.

Regardless, the manufacturers of both aluminum electrolytic capacitors and power film capacitors are more likely to identify with the technical disciplines required to produce carbon capacitors in the farad range.  There are many similarities among “wet” and “dry” type electrochemical capacitors that employ aluminum, tantalum and carbon as dielectrics; there are also similarities between carbon-based capacitor construction and wet type polypropylene film capacitor construction that employ a liquid dielectric fluid to achieve extremely high voltages.

Supercapacitors and Their Unique Value Proposition:
So why does a small market attract so many big name brands in electronics? The reasons can be found in the value proposition that the electric double layer supercapacitor manufacturer offers the design engineer:

High Capacitance Density
Supercapacitors do, in fact, provide the largest capacitance value of any capacitor. And while other dielectrics measure their capacitance in picofarads (ceramics, DC film) and microfarads (tantalum, aluminum), supercapacitors measure their capacitance in millions of microfarads, or in farads. In short, they hold a tremendous amount of charge, which can be released rapidly like a capacitor (pulse discharge) or slowly, like a battery.

Lowest Cost Per Farad
If a customer needs a single capacitor with a discharge of 1 farad or higher, and approached an aluminum electrolytic capacitor manufacturer, the job would be custom and more expensive than a double layer carbon supercapacitor. Thus, supercapacitors operating at capacitance values greater than 1 farad must largely create their own market. To date, supercapacitors have largely been successful in load leveling the power systems of electric busses and in providing burst power for actuated movement (i.e. nacelles for windmills; motor cranking – start/stop, etc.)

Wide Operating Temperature
Although capacitance change with temperature may differ between manufacturer and between supercapacitor technologies, generally speaking, supercapacitors do operate superbly in very cold and very warm environments, whereas lead-acid batteries do not. This makes supercapacitors more desirable than lead-acid batteries for engine-cranking applications in harsh automotive, military and industrial environments. One of the first projects Paumanok IMR worked on in large can supercapacitors was in cold weather start of U.S. battle tanks and armor built by A.E. Edwards Corporation. This was the direct result of prior knowledge that the Russian Army had a tank outfitted with supercapacitors for cold weather start of battle tanks in Siberia.

Reliable, Long-Life Operation
Supercapacitors are extremely reliable. Panasonic (Matsushita) commercialized double-layer carbon supercapacitors in 1972, and their product literature points to continuous long life operation of their supercapacitors that has been field-tested. This is an excellent selling point when supercapacitors are used to replace total or partial functions of a battery. Batteries have short shelf lives and must be replaced frequently. Supercapacitors do not readily degrade and therefore do not need to be replaced. This significantly limits expenditures on maintenance, which tends to be quite costly, depending on the environment in which the battery is located. Therefore, a good marketing strategy for supercapacitor vendors has been to concentrate on battery markets, where maintenance costs are high.

Safe Operation
Supercapacitors operate more safely than batteries with fewer instances of catastrophic failures.  This is because many of the materials consumed in the construction of supercapacitors are designed not only to offer high energy density at operational voltages, but to be inert to the environment as well, thus there is emphasis on developing activated carbon from organic sources and water based (KOH) electrolytes.

Success in Load Leveling and Burst Power:
Supercapacitor manufacturers were able to identify that in a power system, supercapacitors worked best when they were pared with batteries.  The battery provides for steady state power and supercapacitors provide the peak power shaving and overall system load leveling requirements that create a superior power system.  It was also revealed over time that supercapacitors, as standalone components; also outperformed other products for burst power applications.  Using these two “pillars of growth” the supercapacitor industry was able to find traction in consumer electronics circuits requiring protection of CMOS clock functions in case of a power outage; protecting solid state disc drives in server farms in case of power disruption and in load leveling power requirements in transit busses.  It also gained traction for transport start/stop (engine cranking) burst data transmission from satellites, smart metering devices and for adjusting the nacelles in wind turbines.

The Market Faces Unique Challenges in 2019

As Paumanok has documented the global supercapacitor market since 1993 we have a unique perspective on how the market has developed over time.  In 2019 we revisited our research on the global supercapacitor market to reveal an industry that is undergoing some unique challenges.

  1.  Multiple types of technology emerging in a small market;
  2. Limited access to vertical markets in the core product segment.

Multiple Types of Technologies Emerging in a Small Market

We have identified three separate markets based upon the fundamental supercapacitor technology of providing capacitance in the farad range. These are activated carbon, lithium-ion, and mixed metal (hybrid) supercapacitors as described below.

Activated Carbon Supercapacitors:
The majority of supercapacitors deployed today are manufactured from some form of activated carbon material, either a pressed synthetic PTFE or an activated carbon fiber fabric.  Generally speaking, powder type carbon materials which are molded and extruded into anodes represent the approach taken by many of the manufacturers of smaller components that are mass produced because the process lends itself to mass production.  Large can supercapacitors used carbon fabric manufactured in Japan and wound on a mandrel and placed in a large can with separator materials and electrolytes.  The large can segment of the supercapacitor market has intrigued many major scientists at key materials and packaging companies with brands that extend beyond components. PTFE capacitors manufactured from Teflon® are also a small but significant market for defense, space and specialized audio applications.  PTFE capacitors that employ Teflon® are used for high temperature electronics applications to 200 degrees Celsius.

Lithium Ion Supercapacitors:
The lithium-ion supercapacitor market was born out of the need for higher voltage per cell in activated carbon type super capacitors. The solution, which was first suggested decades ago by Mitsubishi Electric in Japan, is to dope the substrate with various amounts of lithium material.

Mixed Metal Supercapacitor Hybrids:
The market for mixed metal oxide (MMO) supercapacitors has blossomed in the past few years for applications in aerospace, primarily for satellite transmissions and deep space communications.  The massive pulse capabilities of the supercapacitor create a burst power charge that is significant. Paumanok has identified that MMO type capacitors also have a promising future for pulsed data transmission from 5G wireless access devices.

Successful EDLC Configurations

Paumanok Publications, Inc. notes that the majority of growth over the time period beginning in 1993 and into 2019 has been in (1) double layer carbon snap mount and (2) large can supercapacitor configurations (This also includes the double layer carbon module assemblies). These large can EDLC (Electric Double Layer Carbon) capacitor product markets have experienced 800% CAGR growth over 26 years, with a significant amount of that growth consolidated within the past seven years.

Limited Growth in EDLC Coin Cells and Cylindrical Markets:

Where we have seen limited value growth over time has been in the older portion of the market—the double layer carbon coin cells and radial leaded capacitor configurations for printed circuit board mounting in consumer electronics (and this is why Panasonic is exiting the EDLC coin cell business).  This is because the newer lithium ion capacitors are also targeting these end-markets with capacitors that demonstrate higher energy density and higher voltage per cell.

Traction in SMD EDLC Chip Packages:

The double layer carbon supercapacitor surface mount “slim-line” designs are just now gaining momentum and have a different business model, so the verdict is still out on how well the SMD chip supercapacitor will fare as a viable load leveling solution for portable electronics, but obviously, since Murata Manufacturing has licensed the technology to manufacture the slim-line EDLC chip designs from Cap-XX, the future vision of their use in portable electronics is alive and well.

Li-Ion Capacitor and Polyacene Capacitor Spin-Offs

The lithium-ion supercapacitor market and the polyacene supercapacitor market developed out of the double layer carbon supercapacitor market.  However, the vendors in Japan (i.e. Taiyo Yuden’s LIC Capacitor), decided to differentiate their product lines from traditional EDLC technology, even though they compete for the same printed circuit board slots.  The lithium capacitor operates at the farad level but has higher energy density and a higher voltage per cell than the carbon capacitor market from which it was developed, making complete systems smaller because of the requirement of fewer cells to achieve the required operating voltage of a given system.

Taiyo Yuden’s LIC Capacitor is designed for use as a storage power source along with solar cells, fuel cells, generators and other applications taking advantage of the LIC’s rapid discharge, long life (compared with conventional EDLC capacitors), and maintenance-free properties. It is also used as the main power source for small devices, including toys, measuring equipment and machine tools, and has targeted the traditional EDLC radial leaded cylindrical capacitor business in professional line voltage applications and consumer electronics (i.e. toy cars).

Hybrid Supercapacitor Configurations:
The hybrid supercapacitor market, or what we at Paumanok call the mixed metal oxide supercapacitor market are of great interest to us because we helped to develop a similar project in the 1980s for pulse supercapacitors in conjunction with Motorola’s Iridium satellite project and Siemens Intelligent Vehicle Highway System in Germany (visionary projects which are at their advent today). The technology was prohibitively expensive in the late 1980s. Today, it is being deployed and should be considered a growth market in the value-added and application-specific segment of the components market as well. Reason being, it offers the design engineer a burst power capacitor that has extremely low equivalent series resistance (ESR).

Summary and Conclusions:

Many important eyes in the global high-tech economy have looked at the purchase of Maxwell Technologies as a resounding note of acceptance of electric double layer carbon (EDLC) supercapacitors (AND High-Energy Density Batteries!) and their potential as a load-leveling device for hybrid and electric vehicles, recouping energy, and burst power.

The Maxwell portfolio also contains EDLC products that could be used for pulsed data transmission in satellites and for deep space communications which also fit well with Tesla and its disparate divisions. Tesla’s acquisition of Maxwell, also puts all the other entrenched manufacturers of EDLC supercapacitors on notice that they too may be the target of acquisition by large auto companies looking to emulate the move by Tesla in their own hybrid and EV programs

In fact, during an important presentation this week we learned from primary intelligent sources that all EDLC companies who produce “Modules” from large cans have already developed “sticky” relationships with transportation-related customers, but all applications to date, other than very specific verticals that involve very specific customers, have been “custom” in nature.

The key growth catalyst for the carbon capacitor market has always been the acceptance of the technology in a major sedan or light truck platform. This has yet to occur, but certainly, one major economic hurdle to this event has been pertinent M&A activity involving a brand name transport vertical, and that day is upon us. So if you are reading this, and you have EDLC module capabilities, the value of what you have been working so diligently on for decades has just increased.  Congratulations. It is important in business to know when to celebrate.

Source: Paumanok Publications, Inc.

Exit mobile version