A Major Breakthrough for All-Solid-State Batteries

Download PDF August 30th, 2023

Enpower Greentech Inc. (EGI), headquartered in San Jose, a global leader in solid-state battery technology and commercialization, has achieved another breakthrough in all-solid-state batteries (ASSB). This new ASSB does not contain liquid electrolytes and is specifically designed to provide ultra-safe, lightweight (energy-dense) batteries for EV and aerial vehicles with 300Wh/kg energy density validated by SoftBank Corp. This breakthrough revealed the superb power performance of Enpower Greentech's lithium metal technology platform and sulfide-based all-solid-state battery platform.

The all-solid-state battery developed by Enpower Greentech for SoftBank Corp. with specific energy 300Wh/kg

"Today, we celebrate another success in this core technology that reduces interface resistance between the cathode and solid electrolyte layer while reducing the weight ratio of the solid electrolyte" shares Dr. Che Yong, Co-founder, and CTO at EGI. "These reductions equate to 300Wh/kg specific energy density for the ASSB cell when coupled with EGI's proprietary lithium metal anode."

Lithium-ion batteries commonly use organic liquid electrolytes for ion conduction. While effective and readily available, the traditional liquid electrolyte may suffer from inherent risks that include fire or ignition from punctures or leakage. In contrast, the non-flammable solid electrolyte used in all-solid-state batteries should greatly improve the safety performance, extend lifetime, broaden operating temperatures, and simplify the battery pack design by eliminating the need for heating and cooling systems.

Dr. Che goes on to explain, "the reason many have struggled to make major breakthroughs in ASSB technology can be understood by the challenges of constructing stable solid-to-solid interfaces using right materials and processes. A solid electrolyte must form a secure and stable bond to the active materials while maintaining ionic and electric conductive paths in the cathode - a task which is far easier using liquid electrolytes." Further he explains, "there is also the challenge of interface resistance for ion conductivity. Increased resistance can reduce battery capacity, power output, and cycle life. Most solid electrolytes have a higher specific gravity weight than liquid electrolytes and in turn increase the battery mass (which reduces specific energy)."

To resolve the challenges facing ASSB development and deployment at scale, EGI has reduced the weight ratio of the solid electrolyte to cathode mixture by using a thin solid electrolyte layer to increase the specific energy to 300Wh/kg, effectively matching energy measures boasted by many lithium-ion batteries.

Enpower Greentech will continue to develop technologies that provide high-energy advanced battery solutions to power the future. This specific all-solid-state battery developed by EGI promises to be a commercially viable option for mass production. EGI plans to begin manufacturing ASSB batteries first for industrial applications by 2025, followed by EV and eVTOL applications later in 2026 in the USA.

Comparing ASSB to liquid electrolyte lithium-ion batteries

Reference: All-Solid-State Batteries (ASSB) are composed from solid materials for all internal components, including a solid electrolyte for ion conduction. Batteries that contain low percentages of liquid components may not be called "ASSB" but may be referred to as solid-state batteries (SSB), quasi-solid-state batteries, or semi-solid-state batteries. When comparing the SSB with the ASSB, all-solid-state batteries promise a wider range of operating temperatures and voltages with improved lifetime and power output.

About Enpower Greentech Inc.

Enpower Greentech Inc. (EGI) is a global leader in solid-state battery technology and commercialization with a clear product roadmap for drones, EV, and E-Aviation markets. Leveraging its dual technology platforms: lithium metal and sulfide-based all-solid-state battery platform, EGI provides advanced battery products with industry-leading energy density, longer cycle life, and higher safety. EGI is headquartered in San Jose and has operations in Ann Arbor (US), Japan, and China.

EGI English PR here:

Softbank English PR here:

Japanese 全固体電池の高エネルギー密度化の技術開発に成功:

to home page to news overview