According to CCTV News, Chinese scientists have recently overcome the “bottleneck” challenge in all-solid-state metal lithium batteries, achieving a leapfrog upgrade in solid-state battery performance: while a 100-kilogram battery previously supported at most a 500-kilometer range, it now has the potential to surpass the 1,000-kilometer ceiling. How was this accomplished? Let’s explore.
To understand this breakthrough, one must first grasp why solid-state batteries have not yet been widely commercialized. Battery charging and discharging rely entirely on the “back-and-forth” movement of lithium ions between the positive and negative electrodes. In this context, lithium ions can be likened to “delivery couriers” in batteries, responsible for transporting electrons from the positive electrode to the negative electrode. The solid electrolyte serves as the “highway” for their “delivery” journey. Commonly used sulfide solid electrolytes are hard and brittle, like ceramics, while the lithium metal electrode is soft as clay. When these two materials are pressed together, it’s akin to sticking clay onto a ceramic plate, resulting in a rough interface with uneven terrain. Such a difficult path significantly impacts the efficiency of battery charging and discharging.
Nowadays, multiple research teams in China have stepped forward, achieving three major technological breakthroughs that enable “ceramic plates” and “putty” to fit together seamlessly. This is expected to resolve the challenges of solid-solid interface contact and completely eliminate the endurance bottleneck of solid-state batteries.
The first is the “special glue” developed by a research team from the Institute of Physics of the Chinese Academy of Sciences in collaboration with multiple institutions—an iodine ion. During battery operation, the iodine ion acts like a “traffic cop,” moving along the electric field to the interface between the electrode and electrolyte. It actively attracts passing lithium ions, filling gaps and holes like flowing sand. Through this patching process, the electrode and electrolyte can be sealed tightly together, overcoming the major bottleneck in making all-solid-state batteries practical.
The second is the “flexible transformation technique” developed by the Institute of Metal Research of the Chinese Academy of Sciences. Scientists used polymer materials to create a “skeleton” for the electrolyte, enabling the battery to withstand stretching and pulling like an upgraded cling film. Even after 20,000 bends or twisted into a fried dough twists shape, it remains intact and completely resistant to daily deformation. Meanwhile, by incorporating some “chemical components” into the flexible skeleton—some of which allow lithium ions to move faster while others can “trap” additional lithium ions—the battery’s storage capacity is directly increased by 86%.
Third is Tsinghua University’s “fluorine reinforcement.” The research team modified the electrolyte using fluorine-containing polyether materials. Fluorine possesses exceptional “high-voltage resistance,” and the “fluoride protective shell” on the electrode surface can prevent high voltage from “breaking down” the electrolyte. This technology undergoes needle penetration tests and high-temperature chamber tests at 120°C without exploding when fully charged, ensuring both safety and endurance are “online.”.
The future has arrived. The breakthroughs in solid-state battery technology are turning the “future” of new energy mobility into “reality.”.
Chinese