Zishine Energy (Shenzhen) Co., Ltd. has announced that its semi-solid battery cells have passed a nail penetration safety test without catching fire or exploding, a result the company describes as a key validation of its semi-solid technology route. The test, conducted at Zishine's reliability laboratory in Shenzhen, involved driving a steel nail through a charged pouch cell to simulate an internal short circuit - one of the most severe abuse conditions a lithium battery can encounter. The cell remained stable, with surface temperature rising only moderately and no visible flame, smoke or rupture. Zishine says the result is consistent with the design intent of its semi-solid electrolyte formulation and supports the company's decision to invest in this technology for portable power products.
Nail penetration is widely regarded as one of the most stringent safety tests for lithium batteries. When a nail pierces a cell, it bridges the anode and cathode internally, creating an instantaneous short that releases large amounts of energy. Conventional liquid-electrolyte cells can vent flammable vapor and ignite under this abuse, which is why nail penetration has become a headline test for demonstrating whether a battery chemistry is fundamentally safer. Zishine says its semi-solid cell's performance under the test validates the choice of electrolyte formulation and separator design, and it provides a useful data point for buyers comparing semi-solid offerings from different manufacturers.
The safety advantage comes from the semi-solid electrolyte itself. Unlike conventional liquid lithium-ion cells, which rely on a free-flowing organic electrolyte that can leak and ignite when a cell is breached, semi-solid batteries use a gelled or polymer-reinforced electrolyte that reduces the volume of free liquid. This limits flammable vapor release after penetration and helps the cell maintain structural integrity. Combined with optimized electrode design and thermal management within the pack, the result is a cell that tolerates abuse conditions far more gracefully than traditional liquid cells. Zishine notes that the exact balance of electrolyte composition was tuned over several iterations in the joint university laboratory, with safety performance as one of the primary selection criteria.
The nail penetration test was not an isolated exercise. Zishine's engineering team ran a battery of complementary abuse tests to build a complete safety picture. These included overcharge testing, where cells were charged beyond their specified voltage limit; short-circuit testing across the external terminals; thermal chamber exposure at elevated temperatures; and drop and crush tests simulating physical impact. Across this suite, the semi-solid cells showed no fire or explosion, with controlled temperature rises that demonstrated stable behavior under fault conditions. The full test matrix is documented in an internal report that Zishine can share with qualified buyers, alongside the supporting photographs and thermal imaging records.
For consumers, what does this mean in practice? A power bank built on semi-solid chemistry is less likely to fail catastrophically if it is damaged, punctured, overheated or subjected to an internal fault. While no battery is risk-free and users should still avoid exposing power banks to severe physical abuse, the semi-solid route reduces the probability of the most dangerous failure mode - thermal runaway leading to fire. This is particularly relevant for portable power products that travel in bags, sit in hot cars, or are used by non-expert consumers who may not handle batteries with industrial-level care. The safety margin also matters for families, students and older users who expect their accessories to behave predictably under everyday accidents.
For brand buyers, passing nail penetration strengthens the sales story. Many of Zishine's OEM clients serve markets where battery safety is a growing concern among end users, especially following high-profile incidents involving damaged power banks. Being able to state that a product's cell technology passed nail penetration without fire is a powerful differentiator, particularly in premium product lines marketed toward travelers, outdoor enthusiasts and families. Zishine says several European and North American clients have requested copies of the test report to support their own compliance and marketing documentation, and the report also helps during retailer due diligence when brands seek shelf placement in safety-conscious channels.
Zishine is careful to frame the result appropriately. The company does not claim that semi-solid batteries are risk-free or that they eliminate all battery safety concerns. Rather, it presents the nail penetration result as evidence of a measurable safety improvement over conventional liquid cells, achieved through real chemistry and engineering rather than marketing language. This disciplined messaging is consistent with the company's approach to other certifications, where it prefers to cite actual test data rather than vague safety claims. The engineering team continues to run safety tests on each new cell revision, so that safety performance is re-verified every time the chemistry or packaging changes.
The result also feeds into Zishine's broader product roadmap. As the company launches portable power products based on semi-solid cells, the safety data generated in these tests supports internal certification processes and helps justify the premium positioning of semi-solid models. Zishine plans to continue iterating its semi-solid electrolyte formulation, targeting higher energy density alongside the safety advantages already demonstrated. The joint laboratory with a university, announced separately, will accelerate this iteration, and the company expects to publish additional safety benchmarks as newer cell generations pass through the reliability lab.
Zishine also intends to use the safety results in consumer education. Rather than only marketing the test to brand buyers, the company plans to publish accessible explainers that help end users understand how to recognize safe battery products and how to use power banks responsibly. This includes guidance on avoiding damaged units, storing devices away from extreme heat, and choosing accessories from brands that can provide actual safety test data. The company believes that a more informed consumer base reduces returns driven by misunderstanding and supports long-term trust in the category.
Brand owners evaluating next-generation power banks can request the detailed safety test reports from Zishine, including nail penetration, overcharge and thermal chamber results. The engineering team can also discuss how semi-solid cells fit into specific product architectures - from slim magnetic power banks to higher-capacity portable power stations. If safety is a priority in your product line, contact Zishine at hushijun@sunhetech.com or +86 138-2522-1556 to request test documentation and discuss a semi-solid OEM/ODM program.
