A Japanese research team has created a quasi-solid-state lithium-ion battery (LIB) that is non-flammable, overcoming the drawbacks of traditional batteries.
The innovation, developed by scientists from Doshisha University and TDK Corporation, combines liquid and solid electrolytes to enhance safety and durability.
Increasing the energy density of positive and negative electrode active materials typically reduces cycle performance and safety, but the innovation offers a balanced solution.
According to the team, the design offers a safer and more durable solution compared to all-solid-state batteries while maintaining high energy density.
“The improved safety and charge/discharge performance demonstrated the feasibility of quasi-solid-state batteries as a near-future technology,” said the team in the study abstract.
A US battery tech firm, Microvast, recently claimed that its all-solid-state EV battery breakthrough offers more energy density and a longer range.
Stable battery interfaces
LIBs are continually advancing to meet growing market demands and support sustainable technologies.
Improving safety, reliability, energy density, recyclability, and environmental compatibility remains critical. While organic electrolytes enable high voltage in LIBs, they require robust safety measures. Solid electrolytes offer a safer alternative, driving interest in all-solid-state batteries.
However, these face challenges in maintaining solid/solid interfaces due to electrode expansion and contraction during charge/discharge cycles. Addressing this requires 'joint interphase' materials that provide elasticity, non-flammability, and high ionic conductivity.
The novel quasi-solid-state lithium-ion battery (LIB) features non-flammable solid and liquid electrolytes.
Promising candidates include elastic polymer electrolytes and non-flammable organic solvents. Recent studies have highlighted advancements, such as using polydimethylsiloxane-based gels and high-concentration lithium salt solutions, to enhance performance.
Despite progress, challenges remain, including slow lithium-ion transfer and interface degradation due to material interactions. Optimising solvation structures and electrolyte combinations shows potential for reducing resistance and improving stability, paving the way for next-generation LIBs.
Solid-state batteries improve safety but face challenges with lithium-ion transfer and disrupted interfaces. Addressing these issues, researchers in Japan developed a non-flammable quasi-solid-state lithium-ion battery, offering enhanced stability, safety, and performance while overcoming the limitations of conventional designs.
The team’s design consists of a silicon (Si) negative electrode and a LiNi0.8Co0.1Mn0.1O2 (NCM811) positive electrode – both of which are regarded as next-generation materials for LIBs – are included in the new battery design.
A solid lithium-ion conducting glass-ceramic sheet (LICGCTM) from OHARA separates these electrodes. The researchers created nearly saturated, non-flammable electrolyte solutions specifically for each electrode to improve compatibility and performance.
Tris (2,2,2-trifluoromethyl) phosphate and methyl 2,2,2-trifluoromethyl carbonate were utilised in the solutions since they were compatible with the solid electrolyte interface and the electrodes.
According to researchers, the resultant quasi-solid-state pouch cells of the 30mAh class showed outstanding electrochemical performance, thermal stability, and ionic conductivity.
The researchers next used accelerating rate calorimetry (ARC), charge-discharge experiments, and electrochemical impedance spectroscopy to evaluate the quasi-solid-state LIB’s thermal stability and electrochemical performance.
Researchers note that the battery’s high charge/discharge capacity, strong cycle performance, and minimal internal resistance change were noteworthy.
Furthermore, even at high temperatures of about 150 °C, the Si-LICGC-NCM811 structure with the corresponding electrolyte solutions demonstrated enhanced thermal stability and very little heat generation from the side reaction, according to the ARC test.
“Overall, the newly developed LIB has the potential to enhance the development of efficient and safer next-generation electric vehicles and cordless appliances like drones. Its widespread application can not only improve user convenience but also promote sustainable economic growth,” said the team in a statement.
The details of the team’s research were published in the Journal of Energy Storage.