The anode is one of the key components of a battery, serving as the space where lithium ions arriving from the cathode are stored. When lithium ions are inserted into the anode, the battery charges. When the ions move back to the cathode, energy is released, discharging the battery. Since the anode directly influences charging and discharging, the material that makes up the anode—known as the anode material—determines the battery’s charging speed and lifespan.
As a result, the importance of anode materials is growing rapidly, and the battery industry is dedicating significant research and development efforts to creating high-performance batteries. Let’s take a closer look at the different types of anode materials and their characteristics through an infographic!
Graphite, the Traditional Leader in Anode Materials
Graphite is the most widely used and longest-standing anode material for lithium-ion batteries. Composed solely of carbon atoms, graphite has a layered structure in which carbon atoms form hexagonal patterns stacked in multiple layers. This orderly layered structure allows lithium ions to be stored stably.
Graphite anode materials are classified into natural graphite and synthetic graphite. Natural graphite has a high lithium-ion storage capacity and lower production costs, but its internal structure expands during charge and discharge cycles, which can shorten battery lifespan. To address this, synthetic graphite is also used. Synthetic graphite undergoes high-temperature heat treatment above 2,500°C, making its internal structure more stable, extending battery lifespan, and allowing for fast charging due to its abundant lithium-ion pathways.
LG Energy Solution has established a strong supply chain for graphite, which offers many advantages. The company signed a Memorandum of Understanding (MOU) with Australian mining company Syrah Resources Limited to secure 2,000 tons of natural graphite annually starting in 2025, with plans to expand the volume over time.
Silicon Anode Materials, Enhancing Energy Density
As battery performance and capacity increase, the need for anode materials that enable fast charging is growing. In this context, silicon is gaining attention as a promising anode material.
Using silicon as an anode material can dramatically increase energy density. While graphite stores one lithium ion per six carbon atoms, silicon can store 4.4 lithium ions per silicon atom. Thanks to this property, silicon anodes offer more than four times the specific capacity per gram compared to graphite, allowing them to store significantly more lithium ions.
As energy density increases, it can extend the driving range of electric vehicles and also facilitate fast-charging design for batteries. Additionally, silicon is also an abundant resource, making it a cost-effective and environmentally friendly material—qualities that make it well-suited for use as an anode material.
Recognizing the potential of silicon anode materials early on, LG Energy Solution began development ahead of the curve. In 2019, the company became the first in the world to apply an anode material containing 5% silicon to a pure electric vehicle. It is now developing “Pure Silicon” technology, which consists of an anode material made entirely of silicon.
Lithium Metal Anode Materials, the Next-Generation Contender
Alongside silicon anode materials, a material that is rapidly emerging as the next-generation anode is lithium metal (Li-metal).
Lithium metal anode materials have an exceptionally high capacity per unit mass, allowing more energy to be stored at the same weight. While graphite’s theoretical capacity1 is 372 mAh/g, lithium metal has a theoretical capacity of 3,860 mAh/g—over 10 times higher than that of graphite. This characteristic enables lithium metal anodes to store significantly more energy.
Additionally, using lithium metal as an anode material allows for the production of a thinner anode. With its high capacity per unit mass, it is possible to create a thinner battery with the same capacity. This improves space efficiency, enabling more batteries to be installed. As a result, it extends the operating time of devices and makes it suitable for systems with high power consumption.
Lithium metal anode materials also offer the advantage of faster charging compared to conventional batteries. Lithium metal anode materials theoretically allow lithium ions to move to the anode, where they are directly reduced and electrodeposited onto the surface without needing to find spaces within the structure. As a result, charging is possible at a faster rate compared to conventional batteries.
To secure lithium metal anode materials, which are gaining attention as next-generation anode materials, LG Energy Solution has taken a proactive approach in development and has been steadily focused on research. The company plans to apply lithium metal anode materials to batteries for low-capacity systems starting at the end of 2027, with plans to expand to high-capacity system products thereafter.
Through this infographic, we have now explored different types of anode materials and their unique characteristics.
LG Energy Solution remains committed to advanced research and development, continuously striving to lead the anode materials market. Stay tuned for more innovations as we enhance our technological competitiveness!
- Theoretical capacity: The maximum content of lithium ions that can be stored in an electrode material within the physical limit. ↩︎
