# Panasonic Energy unveils 150 C solid-state prismatic battery *Sample shipments of the heat-resistant cells begin by December, targeting factory machinery and automotive sensors to cut cooling overhead.* **Published:** September 9, 2026 **By:** Haruto Nakamura **Section:** Batteries & Electric Vehicles — Japan **Format:** Breaking **Confidence:** medium **Source:** https://eastasiabrief.com/batteries-ev/panasonic-energy-unveils-150-c-solid-state-prismatic-battery-222 **Publisher:** East Asia Brief (https://eastasiabrief.com/) --- ## What to know - Thermal limit reaches 150 C to eliminate auxiliary cooling systems in industrial equipment - Engineering samples ship in fourth-quarter 2026 ahead of 2027 commercial production - Panasonic has not disclosed solid electrolyte composition or volumetric energy density ![A technician in cleanroom attire monitors a Panasonic prismatic battery unit inside a testing enclosure. (AI-generated image)](https://eastasiabrief.com/media/2026-09-09-235224d5177d.webp) *A technician in cleanroom attire monitors a Panasonic prismatic battery unit inside a testing enclosure. (AI-generated image)* Panasonic Energy unveiled Sept. 9 a prismatic solid-state battery capable of operating at 150 degrees Celsius, raising its thermal ceiling by 25 degrees to eliminate active cooling systems in industrial equipment. The company, a subsidiary of Osaka-based Panasonic Holdings Corp., operates as Japan's largest battery producer and a primary cylindrical lithium-ion supplier to American electric car manufacturer Tesla Inc. The operating threshold marks a 20% temperature increase from the company's previous 125-degree limit, expanding the operational boundary where cells run without auxiliary heat shields or coolant loops. Chief Technology Officer Shoichiro Watanabe announced the cell at the Battery Japan conference in Chiba, confirming that Panasonic Energy has developed a rectangular prismatic model alongside its existing coin-type prototypes. The prismatic geometry simplifies component placement inside compact machine enclosures, Watanabe said. He noted that flat outer surfaces make automated pack assembly easier than handling circular coin cells. Panasonic Energy is targeting factory automation, tire pressure monitoring sensors and medical equipment requiring high-heat sterilization rather than passenger vehicles for its initial commercial rollout. Industrial machine housings and automotive wheel assemblies generate continuous friction heat, exposing electronic components to temperatures that degrade standard liquid electrolyte chemistries through gas expansion. Solid electrolytes eliminate volatile organic solvents, allowing the cell to maintain charge cycles at 150 C (302 F) without risk of thermal runaway or casing deformation. Medical autoclaves sterilize surgical instruments with pressurized steam at 121 C to 134 C. Standard lithium-ion batteries fail under those thermal cycles, forcing equipment makers to use removable packs. The 150 C rating allows medical suppliers to weld batteries permanently inside sealed surgical equipment. This design removes waterproof gaskets and external charging terminals that fail during repetitive cleaning cycles. Automotive wheel sensors also benefit from the higher thermal ceiling. Tire pressure monitoring units sit millimeters from brake discs where temperatures routinely exceed 120 C during heavy decelerations. Removing ceramic thermal isolation shields and cooling ducting reduces sensor module weight. That mass reduction simplifies wheel balancing and cuts component counts for tier-one automotive parts suppliers. Conventional liquid-electrolyte battery packs allocate up to 15% of total pack weight to cooling plates, pumps and heat exchangers. These systems keep liquid cells below 60 C to prevent chemical breakdown. Solid-state cells avoid that mechanical overhead by operating safely across broader temperature swings. Industrial systems can run passive heat dissipation rather than dedicated refrigeration loops. Coin cells previously limited solid-state adoption to low-power tracking beacons and low-draw telemetry transmitters. Their small footprint restricted total stored energy and prevented automated busbar connection. The new prismatic casing provides wider terminal contact areas. This structural upgrade allows robotic pick-and-place equipment to solder battery terminals directly onto industrial circuit boards. Panasonic Energy also plans to accelerate development of cylindrical batteries designed for humanoid robots, Watanabe said during the press briefing. Cylindrical steel cans provide structural strength and slide cleanly into rounded limb cavities, Watanabe said. He added that humanoid robot joints lack the flat spaces required by rectangular battery packs. The industrial focus sidesteps immediate price competition against Chinese cell manufacturers Contemporary Amperex Technology Co. Ltd. (CATL) and BYD Co., which control over 50% of the world's electric vehicle battery market. South Korean battery producers LG Energy Solution Ltd. and Samsung SDI Co. have focused their solid-state research on automotive applications, targeting commercial vehicle cells near 2027. Japan's Ministry of Economy, Trade and Industry (METI) has categorized solid-state battery manufacturing as a critical economic security asset, granting capital subsidies to support domestic processing equipment. By addressing specialized factory and medical hardware first, Panasonic Energy secures revenue while refining solid electrolyte coating techniques on continuous production lines. Sample shipments of the 150 C prismatic cells and the upgraded coin cells will begin between October and December 2026, the company said. Commercial mass production will follow one to two years after sample deliveries wrap, establishing a volume manufacturing window between late 2027 and 2028. Panasonic Energy has not published an official technical data sheet, leaving unconfirmed whether the cell uses a sulfide-based or oxide-based solid electrolyte and withholding volumetric energy density ratings. Industrial equipment manufacturers will begin thermal cycling tests across specialized machine fixtures once Panasonic begins shipping sample packs in October. ## Impact map | Event | Korea | China | Japan | Global impact | | --- | --- | --- | --- | --- | | High-temperature solid-state cell launch | Samsung SDI and LG Energy Solution face niche industrial competition ahead of 2027 EV solid-state plans | CATL and BYD retain liquid EV cell dominance while Japanese rivals target zero-cooling industrial niches | Panasonic Energy opens industrial sample channel, targeting commercial volume within two years | Industrial device makers cut thermal cooling assembly costs for high-heat factory and sensor installations | ## In this story - **Companies:** Panasonic Holdings, Panasonic Energy - **Tickers:** 6752.T - **Exposed:** Tesla, Contemporary Amperex Technology, BYD, LG Energy Solution, Samsung SDI - **Policy:** Economic Security - **Impact:** Supply Chain, Capex, Cost Structure ## Primary sources 1. finimize.com 2. newsweekjapan.jp 3. biggo.jp 4. wsew.jp 5. luminews.my --- Cite as: East Asia Brief, "Panasonic Energy unveils 150 C solid-state prismatic battery," September 9, 2026. https://eastasiabrief.com/batteries-ev/panasonic-energy-unveils-150-c-solid-state-prismatic-battery-222