Semi-Solid-State Batteries: The Pivotal Leap for Future Power

Semi-Solid-State Batteries: A Critical Step for Future Power

——An Analysis of Differences from Liquid Batteries and Development Trends

With the ever-increasing demands for battery performance in new energy vehicles, energy storage and other fields, traditional liquid lithium batteries are gradually approaching technical bottlenecks. As a core technology for the transition from liquid batteries to all-solid-state batteries, semi-solid-state batteries, by virtue of their remarkable advantages, are becoming an inevitable choice for the industry's development. The following is an analysis from the perspectives of technical differences and development trends. 

I. Core Differences Between Semi-Solid-State and Liquid Batteries

1.Electrolyte Form: Liquid vs Solid-Liquid Hybrid 

Liquid Batteries: Rely on liquid electrolyte as the lithium ion transport medium, with the electrolyte accounting for more than 25%, which is prone to leakage and carries the risk of thermal runaway.

Semi-Solid-State Batteries:Adopt a hybrid design of "solid electrolyte + a small amount of liquid electrolyte", with the electrolyte accounting for only 5%-10%. This drastically reduces the liquid proportion and improves safety. Solid electrolytes, mainly based on oxides or polymers, form more stable ion transport channels.

2.Safety Performance: From Passive Protection to Intrinsic Safety

Liquid BatteriesIn the event of collision, high temperature or overcharging, the electrolyte may leak or trigger thermal runaway, leading to fire and explosion.

Semi-Solid-State BatteriesThrough the high thermal stability and structural compactness of solid electrolytes, they effectively inhibit the growth of lithium dendrites and reduce the risk of short circuit, preventing fire even in extreme collisions.

3.Energy Density: Breaking Through the Ceiling of Liquid Batteries 

Liquid BatteriesTypically have an energy density of 200-300Wh/kg, close to the theoretical limit.

Semi-Solid-State BatteriesBy being compatible with high-voltage cathodes (e.g., high-nickel ternary cathodes) and silicon-based anodes, their energy density can reach 300-400Wh/kg, easily enabling a driving range of over 1,000 kilometers.

4.Fast Charging and Temperature Adaptability 

Semi-Solid-State BatteriesSupport higher-power fast charging (e.g., 400km of driving range supplemented in 10 minutes) and have a wider operating temperature range (-20℃~85℃), with better low-temperature performance than liquid batteries.

II. Inevitable Development Trends of Semi-Solid-State Batteries

1.An Inevitable Path for Technological Transition

Although all-solid-state batteries are regarded as the ultimate goal, their mass production still needs to address challenges such as poor interfacial conductivity and high costs (currently 3 to 5 times higher than liquid batteries). As a transitional solution, semi-solid-state batteries are compatible with existing liquid battery production lines (only 10%-20% of equipment needs modification), featuring lower costs and enabling rapid large-scale application, thus becoming the optimal choice for automakers and battery manufacturers.

2.Driven by Market Demand 

New Energy Vehicles: Consumers have an urgent demand for long driving range and high safety. Models equipped with semi-solid-state batteries (e.g., NIO ET7, IM L6) have already been mass-produced, and 2024 is known as "the first year of mass production of semi-solid-state batteries".

Emerging Fields: Drones, electric Vertical Take-Off and Landing (eVTOL) aircraft, energy storage systems and other fields have higher requirements for high energy density and extreme environmental adaptability, making semi-solid-state batteries an ideal choice.

3.Jointly Driven by Policies and Industrial Chain Collaboration 

Governments around the world have listed solid-state battery technology as a strategic priority. China has planned to achieve a solid-state battery production capacity of over 128GWh by 2025, and leading enterprises such as CATL and BYD are accelerating their layout in this field.

Technological breakthroughs in the upstream and downstream of the industrial chain (e.g., solid electrolytes, silicon-based anodes) are driving down the cost of semi-solid-state batteries, which is expected to drop to RMB 0.9 per Wh by 2025.

4. The Progressive Logic of Technological Iteration

The industry's technological path follows a progressive model of "Liquid → Semi-Solid-State → Quasi-Solid-State → All-Solid-State". By gradually reducing electrolyte content and optimizing material systems (e.g., pre-lithiated silicon anodes), semi-solid-state batteries accumulate experience for all-solid-state technology while meeting current market demands.

III. Conclusion: The Future Role of Semi-Solid-State Batteries

Semi-solid-state batteries are not a "compromise solution", but a crucial bridge connecting the present and the future. They not only solve the safety and performance bottlenecks of liquid batteries, but also gain time for the maturity of all-solid-state batteries. With technological iteration and the emergence of economies of scale, semi-solid-state batteries will dominate the high-end electric vehicle and emerging field markets in the next 5 to 10 years, becoming the core driving force for the upgrade of power batteries.

For enterprises, seizing the industrialization window of semi-solid-state batteries means not only technological leadership, but also a critical step to seize the track of the future energy industry.

References:Industry analysis reports and enterprise technological updates from Autohome, CITIC Securities, Soochow Securities New Energy & Electric Equipment Research Institute, etc.