Today, Ford is considered the victim of disruptive innovation as its competition came from a new type of car company called Tesla. Ford thought their #1 competitor was General Motors." However it turns out they were wrong about this as their real rivalry came from a Silicon Valley startup, focused on electric vehicles and software rather than pickup trucks and horsepower. Today, Tesla’s market cap is roughly six times the combined market cap of GM and Ford.
Kodak made the same mistake, thinking its competition was Fuji Film. Its greatest threat came from the digital camera. Today, my children have no idea what a "Kodak Moment" is.
This is disruptive innovation.
Clay Christensen of Harvard Business School famously defined Disruptive Innovation as “the process by which a smaller company—usually with fewer resources—moves upmarket and challenges larger, established businesses.”
In technology, this happens when something new comes along and changes the way things are done. The old technology needs to find a new niche market to avoid becoming obsolete overnight.
Have lithium polymer (LIPO) batteries disrupted the lithium-ion (18650 and 26650) industry?
The battery industry has seen disruptive innovation over recent years, with lithium-ion products giving way to lithium polymer (LIPO) technology. Polymers are smaller and easier to manufacture in various sizes, but they're also more difficult to mass produce at scale. LIPO’s lack of manufacturing quality and consistency can create major problems. To appreciate the challenges of manufacturing safe LIPO batteries, consider Samsung’s Galaxy S7’s LIPO polymer catching fire and estimated $5.3B recall! Despite these challenges, the benefits of LIPO’s disruptive innovation can be seen in many consumer devices.
Before LIPO technology was developed, lithium-ion batteries were standard in consumer electronics. Consider the replaceable battery in your old laptop, which was battery pack composed of four 3.7V lithium-ion 18650 batteries connected in series (a 4S1P battery). Advanced lithium-ion batteries were available with extra cells in parallel (a 4S2P battery) to extend their lifespan. The 18650 battery pack was a safe, accessible, and a high-quality energy storage solution. Individual battery cells usually came from a high-quality manufacturer like Panasonic, LG, Moli or Samsung; and in most cases, they contained a CID (current interrupter device). Today, however, high-end “ultra thin” laptops like the Lenovo X1 Carbon or Apple MacBook are all powered by LIPO batteries.
Lithium polymer batteries were originally intended for single cell (3.7V) applications, as their quality was insufficient to combine cells in series. Furthermore, cells frequently expanded due to natural "puffing", which would crack cases and led to poor public perception during the early days. These batteries have improved dramatically over recent years, thanks to numerous technological advances. New battery designs have allowed for decreased dimensions, higher quality, and extra capacity.
Due to their thin foil construction, LIPO batteries don't require the same metal casing as 18650 batteries. Instead, they're die cut from a "multi-layer cake" of cathode, anode, and separator. This provides great flexibility, as their capacity can be increased by adding layers to the cake or expanding the overall dimensions. This also allows for the polymer to be cut in various unique shapes, such as the circles required for smartwatch products.
LIPO v lithium-ion — which technology is the winner?
From lightweight laptops to tablets and smartphones, modern technology predominantly uses lithium polymer technology. Said differently, LIPO has disrupted the "low voltage-low capacity-low power" end of the battery industry spectrum. Due to its robust nature, however, lithium-ion and lithium-ion phosphate technology remains dominant for high voltage, high capacity, and high power applications. For example, modern electric cars and bikes use lithium-ion and lithium iron phosphate batteries rather than LIPO technology.
LIPO poses major challenges for industrial applications
The first challenge is related to manufacturing quality, as low-cost, low-quality "tier two" and "tier three" suppliers abound. The industry is driven by low-cost consumer toys like $15 children's drones and talking dolls. For these applications, price is more important than product quality or consistency of production. In these cases, a high percentage of cells fail to meet their rated capacity and calendar life because they experience puffing in the field.
The second problem is related to performance. The high-variation in performance among polymer cells makes them difficult to use in battery packs, both in series and in parallel. When cell performance remains inconsistent over many cycles, a range of problems is likely to occur.
LIPO v lithium-ion batteries for industrial applications
Engineers should consider these guidelines when deciding between LIPOs and lithium-ion batteries for industrial applications:
1. Use industrial-grade LIPOs - You should avoid consumer-grade polymers to save yourself from field failures and endless frustration. Along with failure, consumer-grade cells often reach end-of-life quickly (are discontinued) when manufacturers modify cells for new consumer products. An example of a high-quality LIPO manufacturer is Kokam https://kokam.com/en/. Rose has built battery packs with their cells for exoskeleton applications.
2. Go up to 2S1P - You should use polymers in 1s1p and 2s1p configurations whenever feasible. Use them in series rather than parallel and avoid going above 2s. This helps to minimize the impacts of cell variation.
3. Use matching date codes - All of the modules you use should contain identical matched cells (same date codes) throughout the assembly. Consistency between cells helps to create uniformity in performance.
5. Use 18650 for power applications - For high-load applications, use lithium-ion 18650 or 26650 cells rather than LIPO products. While the weight and size will increase, the overall quality, safety, and performance will be considerably superior. You can observe this in the drone business, with cheaper products making use of LIPO and delivery services utilizing lithium-ion cells.
4. Use LIPOs for energy applications - While standard polymers may be used to power digital electronics, you should generally avoid using them to power mechanical applications such as motors. Instead, you should utilize them in low-load situations. High-current loads cause greater variation in cell performance and faster deterioration over time. If you do use a LIPO for a high-power application, make sure to use a cell designed for high-power.
Example from the Drone and Robotics Industry
The drones and robotics industry is a perfect illustration of how LIPO batteries work in contrast to lithium-ion. For instance, low power (lightweight) consumer grade models like DJI MAVIC PRO are powered by LIPOs while industrial grade drones such as Zipline’s use 18650 cells for their battery pack (at least according this CNET publication)
Lithium polymer batteries may have disrupted the low-voltage end of the battery industry, but they still pose challenges for industrial users. These challenges include inferior manufacturing quality and high performance variation between cells. When using polymers for industrial applications, engineers should avoid consumer-grade polymers, choose 1s1p and 2s1p configurations whenever possible, and use lithium-ion 18650 cells rather than LIPO for high-load applications. If you want to avoid problems and purchase the right batteries, Rose offers a comprehensive selection of industrial-grade lithium polymer (LIPO) cells.
At Rose, we offer an extensive selection of high-quality lithium polymer batteries for industrial applications. Our experts will help you to select batteries and design a custom battery pack that meets your specific needs. Please contact our support team to learn more.