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Onyx

EV-Ready Silicon Anode Material for High-Energy Lithium-Ion Batteries

silicon-graphene composite and battery

Problem

Lithium-ion battery performance has long been constrained by the limitations of graphite anodes. While graphite is stable, widely available, and cost-effective, its relatively low capacity limits battery energy density, creating challenges for applications such as electric vehicles and energy storage systems. Silicon has the potential to store significantly more lithium than graphite, but conventional silicon anodes often experience swelling, cracking, and rapid performance degradation during repeated charge-discharge cycles. The industry has therefore sought a silicon-based anode material that can deliver higher energy density while maintaining durability, manufacturability, and cost competitiveness.

Solution

Onyx™, developed by NanoGraf, is a next-generation silicon anode material designed to improve the performance of lithium-ion batteries. Built on NanoGraf’s patented silicon-graphene composite technology, Onyx stabilizes silicon particles, mitigates volume expansion, and helps maintain electrode integrity over extended cycling.

Unlike many silicon anode technologies, Onyx™ is engineered for compatibility with existing lithium-ion battery manufacturing processes, enabling integration without significant changes to production infrastructure. The material is designed to deliver up to 50% higher energy density than conventional graphite-based anodes while maintaining competitive costs and commercial scalability.

Innovations like Onyx are key to the wider adoption of portable electric tools and machinery, with enormous potential across a wide range of applications.”

— Harold Kung, PhD
Professor Emeritus, McCormick School of Engineering

Benefits

  • Higher Energy Density: Extends EV range by up to 20% compared to graphite anodes.
  • Durability: Maintains >1000 cycles with stable performance under EV operating conditions.
  • Fast Charging: Optimized electrode structure supports quicker recharge times.
  • Cost Efficiency: Manufactured at competitive prices, enabling mass adoption.
  • Scalability: Drop-in ready for existing battery production lines.

Technology & Commercialization Status

Onyx™, NanoGraf’s flagship silicon anode material for electric vehicle batteries, builds on foundational research by McCormick Professor Harold Kung, whose work in advanced silicon-based battery materials helped address key challenges in lithium-ion battery performance, including energy density, durability, and cycle life. NanoGraf has translated this Northwestern-originated innovation into a scalable silicon-anode platform designed for commercial battery applications.

Introduced in 2024, Onyx™ represents the company’s latest generation of silicon anode technology, combining high energy density with manufacturing compatibility and cost competitiveness. The material builds on NanoGraf’s experience supplying advanced battery materials for defense and consumer electronics applications and extends the company’s focus to the rapidly growing electric vehicle market.

To support commercialization, NanoGraf manufactures its battery materials in Chicago and is expanding production capacity through a new facility in Flint, Michigan. This growth is intended to support large-scale domestic battery manufacturing and the increasing demand for advanced materials for electric vehicles and energy storage systems.

Northwestern Inventor

Harold H. Kung, PhD
Walter P. Murphy Professor Emeritus
McCormick School of Engineering

Links

Website: https://www.nanograf.com/