With the rapid growth of industries such as new‑energy vehicles, consumer electronics, the low‑altitude economy, and humanoid robotics, power batteries are entering a new wave of technological advancement. From conventional liquid‑state lithium‑ion batteries to semi‑solid‑state batteries that strike a balance between performance and safety, to all‑solid‑state batteries—often hailed as the “ultimate solution”—each technology has its own strengths and limitations. This article conducts a comprehensive comparison across thirteen key dimensions: electrolyte, separator, cell architecture, energy density, operating temperature range, safety, cycle life, mass‑production cost, major challenges, stage of industrialization, fast‑charging capability, process/production‑line compatibility, and packaging form, offering valuable insights for industry professionals and decision‑makers.

I. Overview of Core Differences
The fundamental difference among the three battery types lies in the physical state of the electrolyte: liquid batteries use an organic electrolyte as the ion-conducting medium; semi-solid batteries maintain an electrolyte content of 5% to 10% while incorporating solid‑state electrolyte components; and all‑solid‑state batteries rely entirely on solid electrolytes, completely eliminating liquid components. The China Automotive Technology Research Center has formally classified batteries into three categories—“solid,” “solid–liquid hybrid,” and “liquid”—at the national standard level, providing a basis for technical classification.

II. Electrolytes and Separators
Liquid‑state batteries use an organic electrolyte—typically lithium hexafluorophosphate (LiPF₆) dissolved in a carbonate solvent—along with a polyolefin separator (PP/PE). The electrolyte provides the ion‑conducting pathway, while the separator physically isolates the positive and negative electrodes to prevent short circuits.

Semi-solid-state batteries employ a “solid–liquid hybrid electrolyte” system, which retains a portion of liquid electrolyte while incorporating solid‑state electrolyte components—either as a solid‑state electrolyte layer coated on the separator surface or integrated with the positive and negative electrode materials. Svolt Energy has pioneered a polarity‑switching solid‑state electrolyte separator transfer technology that forms a continuous, dense solid‑state electrolyte coating on the cathode surface, boosting ionic conductivity by more than 10% and reducing the 200°C thermal shrinkage rate by 20%. Meanwhile, Xingyuan Material has launched its “Gu Rui” series of solid‑state electrolyte composite separators, featuring a delamination temperature as high as 400°C and a thickness of up to 9 microns.

Solid-state batteries entirely employ solid electrolytes, replacing both conventional liquid electrolytes and separators. Solid electrolytes fall into three major technological pathways: sulfide-based materials boast the highest ionic conductivity—reaching 10⁻³ S/cm at room temperature—and are highly favored by Japanese and Korean manufacturers; oxide-based materials offer excellent thermal stability, exceeding 600°C, and have seen extensive domestic investment; polymer‑based systems exhibit superior processability and easier mitigation of interfacial issues. CATL has already launched its third‑generation sulfide‑based composite solid electrolyte, with a room‑temperature ionic conductivity surpassing 7 mS/cm, approaching the level of liquid electrolytes.

III. Structural Composition
Liquid‑state batteries have a relatively mature structure, employing a sandwich‑type configuration of “positive electrode + separator + negative electrode,” which is sealed after electrolyte injection. The manufacturing process primarily relies on wet coating and winding/lamination.

The architecture of semi-solid-state batteries is highly similar to that of conventional liquid‑state batteries, but the separator is typically coated with a solid electrolyte, significantly reducing the amount of liquid electrolyte required. The “separator‑free solid‑state lithium battery technology” jointly unveiled by Tailan New Energy and Changan Automobile further eliminates the traditional separator, highlighting the structural flexibility inherent in semi-solid‑state systems.

The structure of all-solid-state batteries has undergone a fundamental transformation: the separator and liquid electrolyte have been eliminated, and a stacking process is employed to directly stack the cathode, solid electrolyte layer, and anode. Certain designs incorporate electrode‑tab frame printing and isostatic pressing to ensure intimate contact at the solid–solid interface.

IV. Energy Density
Energy density is one of the most pronounced differentiating factors among the three technological approaches. Liquid‑state batteries typically offer an energy density of around 150–300 Wh/kg, lithium iron phosphate falls within the 180–210 Wh/kg range, while mainstream high‑nickel ternary cathodes can reach 250–300 Wh/kg.

Semi-solid-state batteries, by enhancing the voltage plateau and safety margins, have achieved an energy density of 350–500 Wh/kg. BYD’s second-generation semi-solid-state battery boasts an energy density of 360 Wh/kg, with real-world range exceeding 1,000 kilometers; CATL’s condensed‑state semi-solid‑state battery reaches 500 Wh/kg and is slated for mass production and vehicle integration by the end of 2026.

Solid-state batteries boast the highest theoretical energy density, with current commercial products exceeding 420–500 Wh/kg and laboratory‑scale prototypes even surpassing 600 Wh/kg. Guoxuan High‑Tech’s “Jinshi” solid-state battery achieves an energy density of 420 Wh/kg and is slated for small‑batch vehicle integration by the end of 2026.

V. Operating Temperature Range
Lithium-ion batteries can experience a capacity fade of 30% to 60% at –20°C, making low-temperature performance a persistent challenge.

Semi-solid-state batteries, thanks to the thermal stability and favorable interfacial properties of their solid electrolytes, exhibit markedly improved low-temperature performance: at −20°C, capacity fade is kept below 10%, and at −30°C, discharge efficiency remains above 85%; in real-world testing, models from brands such as Hongqi and FAW have even achieved efficiencies of 90% to 95%.

Solid-state batteries offer broader temperature‑range compatibility, but the issue of interfacial thermal‑expansion mismatch remains unresolved. Oxide‑based systems can maintain 85% of their initial capacity at −20°C, whereas polymer‑based systems typically require heating to above 60°C to achieve optimal ionic conductivity.

VI. Safety
The greatest safety concern with liquid‑state batteries is that their organic electrolytes are highly flammable and explosive, and an internal short circuit can easily trigger thermal runaway. In contrast, semi‑solid batteries significantly reduce the proportion of liquid components and incorporate a solid‑electrolyte coating that physically isolates micro‑short‑circuit pathways, markedly enhancing safety. Hive Energy’s membrane transfer‑printing technology lowers the probability of thermal runaway by 25% and raises the self‑heating temperature by 8°C. BYD’s semi‑solid battery has passed rigorous tests—including nail penetration and exposure to 500°C—demonstrating zero combustion and zero leakage.

Solid-state batteries eliminate the risks of electrolyte leakage, combustion, and explosion at the material level, and are widely recognized as the technology with the highest intrinsic safety. However, it should be noted that, as pointed out by Huang Xuejie of the Institute of Physics at the Chinese Academy of Sciences, interfacial contact failure and porosity at the solid–solid interface between the lithium-metal anode and the solid electrolyte remain core challenges for all-solid-state batteries.

VII. Cycle Life
Liquid‑state batteries typically offer a cycle life of 1,000 to 1,500 cycles. Thanks to the synergistic effects at the solid–liquid interface, semi‑solid batteries achieve a cycle life of 2,000 to 3,000 cycles; moreover, the manganese‑based semi‑solid battery jointly developed by Qingtao Power and SAIC has already surpassed 3,000 cycles.

Solid-state batteries theoretically offer the longest cycle life—targeting over 5,000 cycles—but in practice, they are constrained by volume changes at the solid–solid interface and contact degradation. Currently, laboratory‑scale single‑layer cells with capacities of 0.1 Ah can exceed 1,000 cycles; however, when scaled up to 100 Ah, a dramatic drop in performance often occurs. The “battery glue” interface‑repair technology developed by the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, enables Ah‑scale all‑solid‑state pouch cells to stably cycle for more than 1,000 cycles without external pressure, thereby removing a key barrier to industrialization.

VIII. Mass Production Costs
Liquid‑state batteries, benefiting from a mature industrial chain and large‑scale production, have seen their costs fall below 0.5–0.6 yuan per Wh.

Currently, the cost of semi-solid-state batteries stands at 0.82–0.88 yuan per Wh (at the system level), only 8%–12% higher than that of high-nickel ternary liquid‑state batteries with comparable energy density. BYD further claims that its second‑generation semi-solid‑state batteries reduce costs by 15% compared to conventional lithium‑ion batteries.

Solid-state batteries remain expensive, with current cell costs around 2–3 yuan per Wh—roughly 3–5 times that of liquid‑state batteries. Industry‑wide yield rates stand at only 40%–50%, far below the 99%+ seen in conventional liquid‑state batteries. Guoxuan High‑Tech aims to bring solid-state battery costs down to 1 yuan per Wh, equivalent to $140/kWh, and plans to cut expenses by ramping up production capacity to 50,000 tons per year through in‑house development of lithium‑sulfide materials. Meanwhile, Toyota has set a cost target of $100/kWh by 2030.

IX. Major Challenges
Liquid‑state battery technology has nearly reached the limits of material performance, with limited room for further energy‑density improvements and inherent safety constraints. The primary challenge facing semi‑solid batteries is their insufficient capability for high‑current, instantaneous power delivery; the demand for rapid acceleration in premium vehicles remains unmet, necessitating the integration of power capacitors to provide complementary support.

Solid-state batteries face three core challenges: First, interfacial impedance at the solid–solid interface—rigid contact between the electrode and the solid electrolyte can lead to void formation during volume changes upon cycling, resulting in performance degradation; second, the risk of lithium dendrite penetration—particularly in the later stages of cycling, which may trigger short circuits; and third, complex manufacturing processes, with front-end dry‑process technologies and mid‑end hot‑pressing techniques still far from fully mature, yielding yield rates significantly lower than those of conventional liquid‑electrolyte systems. Furthermore, the sulfide‑based approach confronts additional hurdles, including extreme sensitivity to water and oxygen and a propensity to generate hydrogen sulfide gas.

X. Industrialization Phase
Liquid‑state batteries are highly mature, with domestic installed capacity stabilizing at the level of several hundred GWh by 2025.

Semi-solid-state batteries are entering a phase of rapid industrialization: by 2025, domestic installations are expected to reach 31.7 GWh, up 272% year over year; in 2026, installations could climb to 82 GWh, with shipments exceeding 15 GWh; and by 2030, they may capture 26% of the global power‑battery market. BYD plans to begin mass production of its second‑generation semi-solid-state batteries in the third quarter of 2026, with full-scale adoption anticipated by 2027. CATL’s 500 Wh/kg semi-solid-state battery is slated for mass production and vehicle integration by the end of 2026.

Overall, all-solid-state batteries remain in the pilot‑scale validation and engineering‑development stages, with industry consensus projecting small‑batch vehicle integration by 2027 and large‑scale mass production around 2030. Zeng Yuqun, Chairman of CATL, stated that the current technological and manufacturing maturity of all-solid-state batteries stands at Level 4 on a 1–9 scale. Guoxuan High‑Tech is building a 2 GWh all‑solid‑state production line and expects to begin small‑batch production by the end of 2026.

XI. Fast Charging Capability
Currently, mainstream liquid‑state batteries typically achieve 80% charge (from 10% to 80% SOC) in 30–60 minutes. Semi‑solid batteries, however, offer significantly improved fast‑charging performance: CATL’s semi‑solid battery can reach 80% in just 15 minutes, while BYD’s second‑generation semi‑solid battery achieves the same in only 15 minutes. Meanwhile, Gotion High‑Tech’s “G‑Yuan” solid‑liquid hybrid battery supports a 6C charging rate, enabling a 500‑km range boost in as little as 9 minutes.

Solid-state batteries hold the greatest potential for fast charging, with a target of reaching 80% state of charge in 5 to 10 minutes. Among the various approaches, the sulfide-based route is the most promising candidate for ultra‑fast charging, thanks to its ionic conductivity that approaches liquid‑electrolyte levels. However, it currently remains constrained by interfacial polarization at high current densities, and the actual achievable charging rate still requires further validation.

XII. Process/Production Line Compatibility Pathway
This dimension represents a key differentiator in the industrialization challenges of the three battery technologies. Semi-solid-state batteries achieve 70% to 80% compatibility with existing liquid lithium‑ion battery production lines, with retrofitting costs amounting to only 20% to 30% of those for liquid‑cell lines. Furthermore, Svolt Energy’s separator transfer technology enables 100% compatibility with current liquid‑battery production lines.

All-solid-state batteries, by contrast, are entirely different. Their front-end processes must shift from wet coating to dry electrode technology; the mid‑stage requires replacing the conventional winding‑and‑electrolyte‑injection process with a “stacking + adhesive‑frame printing + isostatic pressing” approach; and the back end moves toward high‑voltage formation and capacity grading. With compatibility below 50%, production lines need to be rebuilt or extensively retrofitted, and capital investment exceeds that of traditional liquid‑state batteries by more than 60%, with equipment costs reaching RMB 400–500 million per GWh.

13. Package Configuration
Liquid‑state batteries have the most mature packaging formats, encompassing three mainstream types: cylindrical (such as 18650, 21700, and 4680), prismatic, and pouch. Semi‑solid batteries are largely compatible with existing packaging architectures, with prismatic and pouch designs being the dominant configurations; for example, Svolt Energy has already completed development of its first‑generation 270 Wh/kg prismatic cells. Solid‑state batteries impose more stringent requirements on packaging processes: they must accommodate isostatic pressing for densification and meet special demands for gas tightness and resistance to external pressure, making pouch and prismatic forms the current primary R&D directions. The Dalian Institute of Chemical Physics, Chinese Academy of Sciences, has successfully demonstrated stable cycling of Ah‑scale all‑solid‑state pouch cells. Moreover, sulfide‑based solid‑state systems require rigorous inert‑gas‑sealed packaging to prevent hydrogen evolution upon contact with water, thereby increasing both packaging costs and complexity.

XIV. Summary and Outlook
Based on the foregoing comparison, liquid‑state batteries are technologically mature and the most cost‑effective, making them well suited for applications prioritizing affordability. Semi‑solid batteries strike an optimal balance among energy density, safety, and cost, offering the highest cost‑performance ratio, and are expected to enter large‑scale production by 2026. Meanwhile, all‑solid‑state batteries, as the “ultimate solution” with the highest technological potential, hold transformative promise in terms of both energy density and safety; however, their mass production still faces three major hurdles: solid–solid interfacial challenges, process maturity, and high costs.

The reality in 2026 is that the large-scale mass production of semi-solid-state batteries and the pilot‑scale validation of all‑solid‑state batteries are advancing in parallel. For the industry, semi-solid-state technology is not merely a “transitional solution”; it is a pragmatic choice that balances engineering feasibility, commercial competitiveness, and strategic technological advancement. Meanwhile, all‑solid‑state batteries represent the strategic high ground for the next 5 to 10 years, and the pace of their commercialization will be a key determinant of the global power‑battery industry’s landscape.