Development of a solid-state secondary battery



  • Lithium ion secondary batteries use electrolytic solution, which may lead to accidents such as ignition occurring due to short-circuiting caused by mechanical shock.
  • If the electrolytes are entirely composed of solids, the batteries can be made extremely safe.
  • We started to develop a solid-state secondary battery, seeking further applicability as energy storage components by allowing flexibility in sizing.


  • If the dielectric part of MLCC (ceramic condensers) is replaced with a solid electrolyte, would it function as a battery?
  • Aligning the sintering behavior of different materials is the challenge.

Results and Findings

  • We succeeded in developing an oxide-based, solid-state secondary battery with charge/discharge characteristics and good reliability test results.

Background of the issue

  • NAMICS has already developed the prototyping technology of MLCC, ceramic condensers.​​
  • Our development started based on the hypothesis that replacing the dielectric part of MLCC with a solid electrolyte and an active material would enable us to produce solid-state secondary batteries.
  • Commercialization of a solid-state secondary battery will enable safety, long life, and rapid charging.

Concept of the development​​

  • Solid electrolytes are divided into oxide-type and sulfide-type. The sulfide-type has a high ionic conductivity, but there is a risk of it generating hydrogen sulfide (poisonous) in contact with water.

Therefore, we proceeded with the development with the oxide-type solid electrolyte that makes use of the safer sintering technology that is an advantage of NAMICS.

figure:Solid electrolyte


The sintering behavior of different materials must be aligned.

Results and Findings

  • We studied the materials for the solid electrolyte/active material and succeeded in developing an oxide-based solid-state secondary battery by adjusting their sintering behaviors.

A secondary battery having the charge/discharge characteristics as shown in the figure below and a good reliability test result was completed.

The internal structure of the solid-state secondary battery

figure:white:Current collector + active material / Black:Oxide-based solid electrolyte

Charge and discharge characteristics of 3.2 X 2.5 mm 100-layer product

figure:Charge and discharge characteristics of 3.2 X 2.5 mm 100-layer product

Exhibition ICEP 2018
Presentation title Multilayer ceramic Li-ion secondary battery​​


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