BCI INNOVATION AWARDS: OVERALL WINNERS, 2016–2019 that certain combinations would make a big difference to the electrical performance,” Ellis said. The level of the dopants being added is tiny. But he said that in some instances cycle life was improved by some 40%, dynamic charge acceptance by a factor of two and capacity by 10%. The big breakthrough, however, came when the company secured access to an Advanced Photon Source synchrotron, which is housed at the Argonne National Laboratory and is used in a huge range of scientific disciplines. This allowed it to accurately assess the effect of the proportions of the micro-alloying additions on the micro-structure of the active material. Although the technology had previously been applied to lithium, RSR was the first to apply it to lead. In essence, it allowed them to watch the performance and evolution of the active material micro-structure in the batteries as they cycled in real time by using the APS synchrotron, allowing far more accurate analysis of the dynamics of crystallization phenomena occurring in the battery during charge/discharge cycling. “How and why crystals do, or do not, dissolve is key to improving performance in applications,” Ellis said. “Prior to using this, we knew there was an improvement in performance, but we did not know why. This allowed us to see exactly what was going on and the effect it was having on the battery. “We were able to do this x-ray analysis of the battery plate as it went through the charge and discharge cycle, so we could understand exactly what was going on in the lead. That allowed us to understand how to better engineer the metals to make them more efficient.” Ellis said the ANL welcomed the idea of looking at lead. In the laboratory experiments that followed, when the SUPERSOFT-HYCYCLE alloy was placed against a control lead element typical of standard lead batteries, the careful selection of micro-alloying additions and removal of specific contaminants were found to directly aid in changing the PbSO4 to a more easily dissoluble crystal form — thus prolonging battery life. The cyclability test was based on a specification of a 17.5% depth-of-discharge; normally the cycle rate would be between 800 and 900, Ellis said. Using the RSR alloy it did up to 1,600 cycles. “This is real; it is not a promise or something that may or may not work. It is real now,” Ellis said.
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2018 — Gridtential Energy
New bipolar lead battery architecture
T
hree years ago Gridtential Energy won the innovation award for its silicon joule technology. This combines the traditional benefits of lead acid batteries, such as low cost, recyclability and safety, with a novel bipolar battery architecture. This stacked-cell architecture dramatically reduces the weight of the battery and provides it with the power density associated with lithium technology. John Barton, chief executive of Gridtential Energy, said that by integrating high-volume and lowcost solar manufacturing into the existing lead battery infrastructure, the company has devised an approach that is scalable and should be commercialized, whereas other technologies require novel processing techniques and custom manufacturing equipment. The commercialization process has proved trickier to execute than previously thought, and it wasn’t until the end of April that Gridtential was ready to launch a series of AGM reference batteries produced on East
How the bipolar batteries stack up
Penn Manufacturing’s prototype line. “These are not just samplers but also batteries that are ready to be sold to the market,” said Barton. The first commercial product is a single-block 24V lead battery optimized for deep-cycle applications. A 12V power version will follow late spring, with 48V versions of each appearing in the second half of the year. “Silicon Joule technology can also improve the performance of existing SLI and auxiliary batteries by delivering more cranking power over a wider operating range,” Barton said. “The improved power performance is also extremely important in backup applications, such as telecom and UPS, where the batteries are called upon to deliver large currents in sub-second time frames. “Overall, as demand in high-power applications increases across industries, the Silicon Joule technology’s flexible voltage scalability, thermal management system, recyclability, manufacturability and simplistic design deliver the high dynamic charge acceptance required to meet these evolving performance needs.” Founded in 2011, Gridtential’s material discovery — the use of treated silicon wafers inside the battery — led to the development of Silicon Joule technology. Gridtential has subsequently attracted the world’s largest battery suppliers, and is eyeing new storage markets across the globe as demand for 48V batteries increases for electric-hybrid vehicles. Barton said this innovation is important for the lead battery industry, which faces a unique set of challenges brought on by competition from lithium-ion and the reputation of lead commodities. “Silicon Joule battery technology leverages existing lead recycling infrastructures. But also the amount of lead used in the battery is reduced by up to 40%, significantly decreasing the overall weight of the battery. Continued on page 27
Batteries International • BCI 2021 Yearbook • 25
