The Bakar Fellows Spark Award is designed to accelerate Berkeley faculty-led research to tangible, positive societal impact through commercialization. Through a competitive application process, faculty members are selected as Bakar Faculty Fellows and awarded discretionary research support to fulfill proposed milestones and move their innovative research concepts closer to commercialization.
Liwei Lin is developing safe and deformable soft batteries are desirable for modern products that call for good safety features such as cell phones and good conformability to be embedded onto irregular surfaces in electronics systems. Current Li-ion batteries on the commercial market are rigidly packaged and hermetically sealed to prevent: 1) the intrusion of moistures which degrade performances; and 2) the leakage of toxic and flammable electrolytes due to mechanical damages. On the other hand, various deformable/stretchable batteries have been reported in research articles and they have shown good conformability but suffered from significant performance degradation over time with low operation hours in the ambient environment. The fundamental challenge for safe and flexible battery is that both the modulus of elasticity and gas permeability of materials are inextricably linked. A conformable battery needs to use materials with low elastic modulus containing a high amount of free volume between polymer chains for good flexibility. However, this allows the penetration of moistures for performance degradations. Furthermore, the conventional organic electrolytes are both toxic and flammable while the flexible polymer package materials can be easily damaged without surviving in the working environment. In a drastic new approach, Lin’s team has proposed key innovations to circumvent the common battery safety and hermetic sealing issues, including the usage of a non-toxic, aqueous hydrogel electrolyte instead of organic electrolytes.