Nevada leads scramble to improve batteries


In August 2009, the Obama administration strongly pushed forward its goal to place 1 million plug-in electric vehicles on the road by 2015 and remake the U.S. automotive industry at the same time.

The president announced 43 federal government grants for the purpose of promoting advanced battery technology development and manufacturing within the United States, totaling $2.4 billion under the American Recovery and Reinvestment Act of 2009. These grants were targeted to stimulate a domestic advanced battery industry that would partner with the automotive industry to create powerful new storage batteries for full-sized electric and plug-in hybrid-electric vehicles, as well as create new jobs for the country.

Thankfully, some of that money came to Nevada.

The Chemetall Foote Corp. in Silver Peak received $28.4 million under the category of "advanced battery supplier manufacturing facilities."

Silver Peak is in Esmeralda County, located about 220 miles northwest of Las Vegas. It is one of the oldest mining towns in the state. The nearby Clayton Valley sits on an extinct volcano caldera that is still rich in minerals today. Gold and silver were discovered in the area in 1863 and a boom town quickly formed around nearby fresh water springs the following year.

Like most mining boom towns, Silver Peak's fortunes ebbed and flowed over the next 100 years, depending on the success of local mining operations. By 1948, the gold and silver resources in the region had already been extracted and a devastating fire almost destroyed the town. The population of Silver Peak dwindled during the next 60 years and in 2008 was counted at 128 residents. The total population of Esmeralda county, including Goldfield, numbered 1,024 residents.

In 1966, the Foote Mineral Co. came to the region to set up mining operations. Instead of gold and silver, the company started mining lithium carbonate from the rich liquid brine deposits that were left behind by evaporated geothermal activity from within the inactive volcano. Lithium is one of the most common elements in the world, but likes to attach itself to other materials. Extracting lithium from hard rock cores is expensive. Extracting and processing lithium when found in a liquid salt form is much less difficult and costly.

The Clayton Valley has been a rich source of lithium carbonate brine for more than 40 years with concentration levels at 200 parts per million, helping the Chemetall Foote Corp.'s ponds near Silver Peak become the largest production facility for lithium carbonate and lithium hydroxide in the United States. For most of its 40 years of operation, the demand for this mineral resource was modest, mostly from the ceramic and glass industries. This all changed in 2004, when the development of lithium-ion battery cells as power sources for portable electronics started increasing the demand for this mineral resource worldwide.

Rechargeable lithium-ion battery cells have three components that help create electrochemical energy. These components allow the power of that energy to flow through an external load like an electric motor, enabling that external device to do work. These three components inside the battery cell are the anode, cathode and electrolyte.

The anode is the positively charged electrode or "plus" side of the battery cell. The cathode is the negatively charged or "minus" side of the battery cell. The electrolyte is the medium between the anode and cathode where chemicals mingle to create a syrup or "slurry" that interacts with the anode and cathode materials. The electrolyte allows energy to travel through the battery cell between the anode and cathode during charge and discharge cycles.

In a rechargeable lithium-ion battery cell, lithium salt compounds are used in the electrolyte slurry to create ions. Lithium ions are lithium atoms that are either missing an electron (called a cation) or have one extra electron (called an anion). Lithium atoms found in nature have only one electron in their outermost valence shell, so they can be "ionized" to shed or acquire excess electrons relatively easily compared to other atoms during a battery cell recharging cycle. Lithium atom cations that are missing an electron tend to migrate from the electrolyte to the negatively charged cathode of the battery cell. Lithium atom anions with an excess of electrons tend to migrate from the electrolyte to the positively charged anode side of the battery cell. The basic lithium salt electrolyte chemistry remains unchanged. It is just the quality of the atoms that changes state during the charge and discharge cycles of the battery cell.

This property is what makes lithium-ion battery cells so much more efficient than lead-sulfuric acid battery cells but also makes them somewhat more delicate in comparison. In lead-acid battery cells, the electrolyte, anode and cathode of each cell must all undergo severe molecular changes during each charge and discharge state. Lead, sulfur and oxygen atoms must be pulled apart from molecules and reformed into different types of molecules during each change of state, consuming much more electrical energy internally in the battery cell during both parts of the discharge/recharge cycle.

However, because of these characteristics, industrial lead-acid battery cells are much more tolerant of abuse during overcharging or when undergoing heavy current drain while dropping to their lower threshold of current capacity. Lithium-ion battery cells are not as forgiving under extreme conditions.

Overcharging a lithium-ion battery cell or discharging it beyond its lower threshold can permanently damage the lithium electrolyte of the lithium-ion cell, making it unable to perform at all. Battery Management System electronics must be integrated into lithium-ion battery packs to monitor and protect the performance of each cell. These electronic control systems must be capable of disconnecting each individual cell from a charging source or from a heavy work load under extreme conditions. If battery developers are successful in overcoming these engineering problems, larger scale lithium-ion batteries can become an economic engine for the U.S. economy by creating new portable power applications, as well as related jobs in multiple industries.

The little town of Silver Peak can lead the way.

Stan Hanel has worked in the electronics industry for more than 30 years and is a long-time member of the Electric Auto Association and the Las Vegas Electric Vehicle Association. Hanel writes and edits for EAA's "Current Events" and LVEVA's "Watts Happening" newletters. Contact him at stanhanel@aol.com.

 

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