Battery Materials Synthesis

NREL's development of inexpensive, high-energy-density electrode materials is challenging but critical to the success of next-generation battery designs tailored across energy applications.

Increasing energy and power demands across the United States require tailored solutions and integrated systems. Electrochemical energy storage offers a proven approach to meeting power needs when and where energy is needed. However, materials synthesis is crucial to designing durable and reliable systems that withstand thousands of charge/discharge cycles and harsh chemical, thermal, and mechanical environments while meeting the unique needs of stationary or electric vehicle (EV) batteries. NREL researchers work together with industry partners to address these challenges and evaluate new materials and processes to maximize energy performance.

NREL researchers continue to explore refinements and emerging battery technologies, such as lithium-air, magnesium-ion, and solid-state technologies. NREL's energy storage materials research concentrates primarily on the composition and coating of electrodes as well as thermal interface materials including greases, phase-change materials, thermoplastics, and graphite to maximize battery performance.

Coatings

Unstable interphases and surface side-reactions between organic electrolytes and electrode surfaces can trigger interface instability and durability problems in batteries. These issues typically shorten battery lifespan and diminish reliability.

NREL research has achieved greater battery stability through both conventional and innovative methods. The lab's introduction of metal oxide and hybrid inorganic-organic surface modification via atomic layer deposition has provided innovative and cost-effective methods to mitigate lifespan and reliability concerns.

Atomic Layer Deposition

NREL and its partners have developed a breakthrough method for applying coatings directly on as-formed composite electrodes using atomic layer deposition (ALD). ALD is the current state-of-the-art method for applying conformal thin film coatings to highly textured surfaces. These coatings have been shown to enhance cycle life and abuse tolerance in lithium-ion (Li-ion) batteries. Improvements in performance can be traced back to mitigation of deleterious side reactions and prevention of mechanical degradation. These coatings must be optimized to match electrode material and thickness.

Advanced Manufacturing

Building on the success of optimized electrode coatings in improving Li-ion battery performance, NREL is working with university collaborators to develop a new electrode coating method that transfers the ALD process into an in-line, roll-to-roll format that can be integrated with manufacturing methods.

Electrodes/Anodes

Significant advances in battery energy density and rate capability are needed for electric-drive vehicles to offer enhanced reliability, durability, and safety. Materials with high energy densities often fracture, degrade, and rapidly lose capacity due to expansion and contraction when the battery is charged or discharged at a high rate. NREL has managed to increase battery lifespan, rate capability, capacity, and safety through the development of novel nanostructured electrode materials.

Nanotechnology

Scientists at NREL have created crystalline nanotubes and nanorods to address Li-ion battery thermal management, weight, and conductivity issues. NREL's high-performance, binder-free, carbon-nanotube-based electrodes can optimize battery charging and reduce swelling and shrinking that can shorten electrode lifespan. An array of custom-built apparatus makes it possible for NREL to conduct nanostructured synthesis research.

Metal Oxide Anodes

Transition metal oxides are capable of a significantly larger reversible capacity than commercial-grade graphite. Molybdenum oxide can produce a stable capacity nearly three times that of conventional graphite anodes. Iron oxide is among the most abundant and least expensive elements and can outperform many other materials when nanoparticles are used in electrodes produced with NREL's innovative fabrication techniques.

Silicon Anodes

NREL is working in partnership with other national labs via the Silicon Consortium Project to investigate the use of silicon as a possible viable alternative to graphitic carbon as an anode material. Because of its high capacity and availability, silicon has the potential to improve energy density and reduce costs. However, several issues may limit its utility, including swelling upon lithiation (which can lead to particle cracking, particle isolation, and electrode delamination) and electrolyte side reactions (which can affect cycling efficiency). Additionally, understanding the mechanisms of solid electrolyte interphase formation and failure is necessary to enable functioning silicon anodes in Li-ion batteries.

Critical-Material-Free Battery Technologies

As the demand for electric vehicle fast charging at levels of 350 kilowatts or higher continues to rise, new approaches are needed to avoid considerable cost and grid-resiliency impacts. Innovative critical-material-free behind-the-meter energy storage solutions addressing these issues could apply to other short-duration, high-power-demand electric loads as well.

Behind-the-Meter Energy Storage

NREL is working in partnership with other national labs via the Behind-the-Meter Storage Consortium to develop novel, critical-material-free battery technologies to lower operational costs for energy-intensive industries by absorbing excess energy during low demand times and discharging when needed. Tailored energy storage system designs can leverage a strategic energy supply for mining operations, manufacturers, data centers, and more. 

Contacts