As the search intensifies for batteries beyond today's lithium-ion technology, researchers are paying growing attention to electrode materials that can store more energy while supporting lower-cost and more sustainable energy systems. Among the candidates now under the spotlight is black phosphorus, a layered material widely regarded as one of the most promising anodes for alkali metal-ion batteries. A new review published in Science Bulletin explains why black phosphorus has generated such excitement—and why turning that promise into practical devices remains a major challenge.
The appeal of black phosphorus is easy to understand. It combines an exceptionally high theoretical capacity—around 2596 mAh per gram—with favorable ion-transport properties and a tunable electronic structure. These features make it attractive not only for lithium-ion batteries, but also for sodium- and potassium-ion systems, which are increasingly viewed as important alternatives for large-scale and sustainable energy storage.
But the same material that looks so powerful on paper can perform poorly in real batteries. The review points out three persistent obstacles: black phosphorus is chemically unstable in air and moisture, it undergoes severe volume expansion during alloying reactions, and it tends to form unstable interphases with electrolytes during cycling. Together, these problems can trigger structural pulverization, interfacial degradation, and rapid capacity loss.
Rather than focusing on one narrow solution, the article maps out an entire engineering toolbox for overcoming these barriers. It reviews how researchers are improving black phosphorus through carbon integration, metallic reinforcement, transition-metal-compound hybrids, polymer encapsulation, and porous MOF/COF frameworks, as well as through the development of few-layer black phosphorus structures. Across these strategies, the goals are similar: improve electron and ion transport, buffer mechanical strain, stabilize the solid electrolyte interphase, and preserve structural integrity during repeated cycling.
The review also highlights an important broader message: black phosphorus should not be viewed simply as a high-capacity material, but as a platform whose performance depends critically on structure and interface design. In other words, future progress will likely come not from black phosphorus alone, but from how it is synthesized, protected, hybridized, and integrated into multifunctional electrode architectures.
By organizing progress across lithium-, sodium-, and potassium-ion batteries, the authors provide more than a literature summary—they offer a roadmap for the field. Their conclusion is that black phosphorus-based anodes still face substantial barriers to practical deployment, but continued advances in scalable synthesis, composite engineering, and interfacial regulation could move them much closer to real-world applications. For researchers developing next-generation high-energy batteries, the review provides both a timely assessment of the challenges and a guide to where the most promising opportunities may lie.
