LG Energy Solution Says EV-Size Solid-State Batteries Still Resist Mass Production

Solid-state battery prototypes are already moving cars, but that does not mean factories can make the same technology reliably, affordably and in automotive volumes. LG Energy Solution has now put that tension plainly: large-format production remains the central obstacle separating promising test vehicles from mass-market electric cars.

“The problem with solid state is large-scale production,” Robert Lee, president of LG Energy Solution North America, said during an August 2026 media roundtable at the company’s newly opened battery plant in Lansing, Michigan. Lee said the technology offers very good energy density, but added that “if you’re making very large form factors, most companies are struggling.”

His assessment does not dismiss solid-state chemistry. It defines the boundary between a successful cell demonstration and a commercially viable vehicle battery. A small cell can perform well under controlled conditions without proving that thousands or millions of larger cells can be produced with consistent interfaces, material thickness, pressure control, durability and acceptable scrap rates.

Why a working prototype is not a production system

Recent vehicle programs show that solid-state development is advancing. Mercedes-Benz reportedly drove a prototype EQS equipped with Factorial Energy cells nearly 750 miles on one charge. BMW installed an all-solid-state battery supplied by Solid Power in a prototype i7, while Stellantis is testing a semi-solid-state pack in a Dodge Charger Daytona EV. BYD, CATL, Geely and other Chinese manufacturers are targeting pilot programs in 2027.

Those demonstrations establish that developers can integrate emerging cells into vehicles and test them under increasingly realistic conditions. They do not independently establish production yield, lifetime, manufacturing cost or repeatability. Reported range and commercialization targets also remain company claims rather than verified performance available to ordinary buyers.

Scale matters because an EV pack is not simply a larger version of a laboratory cell. Solid electrolytes must be thin enough to support energy density and ion transport while retaining mechanical integrity. Interfaces between the electrolyte and electrodes must remain uniform, and some designs require controlled pressure at cell and module level. Lithium-metal anodes can add further sensitivity to material loss and processing conditions.

A recent solid-state battery ecodesign study, drawing on 49 studies and consultations with seven battery experts, identified cell design, material selection, manufacturing cost, interfacial resistance and degradation among the unresolved issues. It also found that lithium-metal anodes and solid electrolytes remain major environmental and cost hotspots, while production data are limited because many processes are still immature or confidential.

That helps explain why scaling is more than a matter of installing additional equipment. A process that creates acceptable cells individually may generate too much variation or scrap when accelerated. Tighter dry-room controls, electrolyte coating, component-thickness optimization and digital process monitoring can improve consistency, but each must be validated on production equipment. Thinning a solid electrolyte, for example, can improve energy density and reduce material use while also reducing its resistance to mechanical failure. The benefit therefore comes with a manufacturing and durability constraint.

Smaller products may get the technology first

Lee expects specialized applications and smaller formats to arrive before mainstream EV batteries. “You will see that in your smartphones probably a decade before you would see it in EVs,” he said. That sequence follows the manufacturing challenge: smaller cells require less active area over which defects, interface variation and pressure must be controlled.

The prediction is not a universal launch date for either market. It is a relative assessment that consumer electronics may be able to absorb solid-state cells much earlier than mass-produced cars. EV batteries also face demanding requirements for pack-level durability, thermal management, crash protection, serviceability and long-term performance across wide temperature and charging conditions.

LG Energy Solution is keeping nearer-term options open

Rather than waiting on one chemistry, LG Energy Solution is pursuing several battery paths. It is developing lithium-manganese-rich cells with General Motors, which says the technology will enter full-size trucks and SUVs beginning in 2028. GM claims more than 400 miles of range at roughly the cost of lower-cost lithium-iron-phosphate batteries, although those outcomes have not yet been independently established in production vehicles.

LG Energy Solution also plans to manufacture large-format 46-series lithium-ion cells at its upcoming Arizona factory and is preparing a sodium-ion pilot program for stationary energy storage. “We just want to have all those options open,” said Devon Wilson, vice president of sales and marketing at LGES Vertech.

That diversified approach reflects different engineering priorities. Automotive cells must balance energy, power, life, safety, cost and manufacturability; stationary storage can accept different weight and volume tradeoffs. No single chemistry must win every application to become commercially useful.

For drivers, the practical distinction is between a prototype milestone and a production milestone. A long-range demonstration can show what the chemistry may enable. Commercial readiness requires factories to reproduce large cells at high yield, integrate them into durable packs and meet a price automakers can sustain. LG Energy Solution’s message is that the industry is making progress on the first task, but has not yet solved the second at EV scale.

By Thomas Caldwell — AMI’s senior editor for mechanical and mobility engineering, covering vehicle electronics, systems integration, electrification, chassis systems, propulsion, and safety policy.