The battery market is rapidly evolving. Today, the challenge is no longer simply to build batteries with better performance. Now, securing a competitive edge in future technologies is key to claiming industry leadership. Amid this trend, solid-state battery is garnering significant attention.  In this article, we take a closer look at why solid-state batteries are hailed as next-generation battery technology and examine the technological strategies LG Chem is prioritizing.

Limitations of Conventional Batteries: Why Change Is Essential

Batteries typically consist of four key components: the cathode, anode, electrolyte and separator. Among these, the electrolyte serves as the pathway for ion movement, making battery operation possible.

Lithium-ion batteries using liquid electrolytes are most widely used in electric vehicles and smartphones today. However, liquid electrolytes are vulnerable to heat and physical impact and their performance is sensitive to temperature fluctuations. As a result, they have inherent limitations in both safety and performance.

Issues such as battery fires in everyday applications or reduced performance in cold winter conditions stem from these characteristics. Against this backdrop, the market is seeing growing demand for batteries that are safer, longer-lasting and capable of delivering higher performance. Amid this trend, solid-state batteries are the technology capturing global attention.

How Solid-State Batteries Transform the Industry

As the name suggests, a solid-state battery replaces the liquid electrolyte with a solid electrolyte. What benefits does this bring?

First, solid electrolytes are far less flammable, greatly enhancing safety by reducing fire risks. They also enable more efficient use of internal battery space, boosting energy density and thereby extending electric vehicle driving range.

Thanks to their solid properties, they are more resistant to heat and impact, which can extend battery life. Solid-state batteries also  deliver more stable performance across a wider range of operating temperatures, from extremely cold winters to hot summers. Additionally, eliminating liquid electrolytes simplifies battery design and offers advantages in miniaturization and lightweighting.

Why LG Chem Is Focusing on Sulfide-Based Solid-State Batteries

Solid-state batteries are broadly classified into three categories based on electrolyte materials. Among them, LG Chem is focusing on sulfide-based solid-state batteries, which are considered particularly promising for high-performance applications.

Sulfide-based solid-state batteries offer high ionic conductivity*, facilitating easy ion flow and making them ideal for high-power demands like electric vehicles. With this approach, LG Chem is developing solid-state batteries that combine sulfide-based solid electrolytes with high-nickel NCM cathode materials* capable of delivering high energy density.

* Ionic conductivity: a measure of how effectively ions move through an electrolyte

* High-nickel NCM cathode material: a ternary cathode material composed of nickel, cobalt, and manganese, with a high nickel content that contributes to superior energy density, driving range, and output

However, this combination also presents a major technical challenge: the high reactivity between NCM cathode materials and sulfide-based solid electrolytes.

The Core Challenge in High-Performance Solid-State Batteries

Direct contact between NCM cathode materials and sulfide solid electrolytes triggers unwanted interfacial reactions, leading to battery performance degradation and reduced lifespan. This is widely recognized as one of the most critical challenges in solid-state battery development. To address this issue, LG Chem is focusing on two key technology areas.

1. Coating Technology to Improve Interfacial Stability

Coating technology forms a protective layer on the cathode material surface. LG Chem’s approach blocks direct contact between NCM cathodes and sulfide solid electrolytes while ensuring smooth lithium-ion transport. This protective layer must not only prevent contact but also achieve uniform coverage and high ionic conductivity, demanding advanced technical sophistication.

LG Chem is also working to develop cost-competitive processing technologies that enable more precise coating formation while cutting costs. Wet coating with organic solvents commonly applied to create uniform coatings on cathode surfaces. However, wet coating is typically used for uniform cathode surface coverage. To solve this challenge, LG Chem is developing dry coating technology that is easily integrated into existing production processes.

2. Morphology Control Technology to Improve Structural Stability

Another challenge arises when reactions between sulfide-based solid electrolytes and cathode materials cause cracks inside cathode particles.

These cracks disrupt internal electron and ion flow, ultimately degrading performance and shortening lifespan.

LG Chem addresses this by doping specific elements into the cathode crystal lattice to suppress internal cracking while optimizing the lithium-ion pathways. This technology ensures  structural stability  under high-rate charge and discharge conditions, securing long-term reliability.

How LG Chem Is Preparing for the Solid-State Battery Era

Around the world, automakers and battery companies are accelerating the development of solid-state batteries. They’re widely seen as the core technology that will determine next-generation battery market leadership.  In this landscape, LG Chem is securing key commercialization technologies through proprietary materials expertise, continuous investment in R&D and close collaboration with customers.

Currently, lithium-ion batteries using high-nickel NCM cathode materials from LG Chem’s Cheongju plant achieve approximately 400 Wh/kg. By applying sulfide-based solid electrolytes to solid-state battery systems, LG Chem is developing solid-state batteries by integrating sulfide solid electrolytes, targeting 500 Wh/kg by 2030 with intensified R&D efforts.

LG Chem also sees strong value in solving challenges together with customers in real-world manufacturing environments. These collaborative solutions further solidify company’s technological capabilities.

Once Solid-state batteries reach commercialization, they will extend EV ranges, shorten charging times and enhance safety beyond current levels. This goes beyond battery improvements, serving as a pivotal turning point for future mobility and the broader energy industry.

This is why LG Chem goes beyond cathode material development to establish new standards for future battery technologies. Through continuous innovation, LG Chem will continue to strengthen its competitiveness in the next-generation battery market and contribute to building a better energy ecosystem.

By Byeongjin Choi

Research Fellow and Project Leader, ASSB CAM PJT, Advanced Materials R&D, LG Chem

※ Some images in this content were generated using AI.