Dawn of the Lithium-Ion Battery Era
Author: Peter Gibson, Director of Sales, LG Chem – Energy Storage Systems
Can technologies first discovered more than two centuries ago have the potential to make dramatic and far-reaching changes to today’s manufacturing and service industries? The surprising answer is “Yes” – and the disruptive impact advanced batteries will have on both manufacturing and service industries are only now being realized, creating many business and career opportunities for today’s engineers.
The humble battery has been around since the days of Benjamin Franklin in the mid-eighteenth century. We’re all familiar with lead acid and nickel cadmium cells, but these do not possess the energy densities or cycle life required for more challenging applications, such as those found in electric or hybrid vehicles, or electric grid support services where more frequent cycling is a basic requirement. Since Sony launched the lithium-ion battery 25 years ago, there have been relatively rapid advances in the technology such that in its January 16-22, 2016, edition, The Economist magazine said “In one form or another, the lithium-ion battery is the technology of our time.”
Driven by the need to comply with emissions targets, global vehicle OEMs have increased the number of (hybrid electric vehicles) HEV, (plug-in-electric vehicles) PHEV and (electric vehicles) EV (collectively commonly referred to as ‘xEV’) platforms in their product ranges. To enable market penetration, battery vendors have had to deliver systems with superior performance (cycle life, degradation, etc.) and lower costs. Lithium-ion’s high energy densities, both by volume and mass, have made it the chemistry of choice for the majority of automotive applications where both size and weight are critical. Battery suppliers have been successfully finding ways to deliver better batteries at lower price points to achieve greater market competitiveness for xEV products.
Increasing adoption of lithium-ion batteries in the automotive market is one of the key influencers behind the surge of interest in deploying lithium-ion batteries for a wide range of stationary applications, from the modest kWh-scale residential battery to multi-hundred MWh energy storage systems for grid applications. Independent developers of energy storage projects and large electric utilities understand that advances required by automotive OEMs to achieve greater vehicle range (with batteries that are durable and uncompromisingly safe, and at costs that need to dramatically reduce if xEVs are to be sold at prices comparable with gasoline vehicles) present an opportunity for batteries to be used for a wide range of grid-connected applications.
Grid applications typically fall into two distinctly different segments: short duration, power-centric; and longer duration, energy-centric. Power-centric applications are those where a battery must respond very quickly to changes in charge/discharge levels with the ability to deliver rated power for periods of 12-30 minutes, as is required for grid ancillary services such as frequency regulation. Energy-centric applications require batteries to charge/discharge for periods of 1 hour or more, typically up to 4 hours, for capacity resource needs. Lithium-ion batteries are being used today to provide cost-effective solutions for power and energy applications, with certain lithium chemistries having characteristics that lend themselves more to power or energy. There are other chemistries such as high temperature sodium, aqueous ion, and various flow battery chemistries, but lithium-ion is today’s preferred solution and is often specified in customers’ RFPs, primarily because of the expected improvements in performance and cost as a result of the technology being adopted by two large industries: automotive and electric supply services. As the incumbent battery technology for xEVs, it’s difficult to see lithium-ion’s dominance fading in the near- or mid-term.
Growth in the market for grid applications is dependent on several factors. Costs need to continue to fall; costs of battery-only DC blocks, excluding the DC/AC inverter, have fallen by ~70% in the past 3-4 years, and are expected to reduce a further 40% in the next 3-4 years. There have to be changes in regulatory policy so that the advantages of fast-acting batteries versus today’s conventional generators used for ancillary services can be properly compensated. Utilities need to become confident in the reliability of this new technology before using batteries as part of their integrated resource planning analyses. And there’s the rather interesting dilemma on whether a battery is part of a utility’s generation or wires (transmission and distribution) business – it’s an asset that crosses a long-established divide within a utility’s operations!
As with any early-stage technology in an evolving market where the rules are still in development, the challenges and opportunities for early career engineers are immense. Many of the challenges relate to mechanical engineering disciplines such as: optimizing battery system life and performance through enhanced thermal management; design of battery modules and rack systems for ease of installation and servicing; configuring battery systems so they become more of a ‘product’ than a bespoke solution for each project; and designing automotive battery packs so they easily can be used in stationary applications at the end of the vehicle’s life.
Battery energy storage technologies for grid applications are at a very early stage in their evolution. They are competing with traditional technologies that have been used for more than one hundred years. Yet, within less than 10 years of development, lithium-ion systems secured orders from utilities in California in an open competition with conventional fossil-fueled alternatives for grid operations support. This was, in my opinion, the moment when the dawn of the lithium-ion era truly began.