No abstract

Great efforts have been devoted to the development of high-energy-density lithium-ion batteries (LIBs) to meet the requirements of emerging technologies such as electric cars, large-scale energy storage, and portable electronic devices. To this end, silicon-based electrodes have been increasingly regarded as promising electrode materials by virtue of their high theoretical capacity, low costs, environmental friendliness, and high natural abundance. It has been noted that during repeated cycling, severe challenges such as huge volume change remain to be solved prior to practical application, which boosts the development of advanced cross-linked binders via chemical bonds (CBCBs) beyond traditional PVDF binder. This is because CBCBs can effectively fix the electrode particles, inhibit the volume expansion of Si particles, and stabilize the solid electrolyte interface and thus can enable good cycling stability of silicon anode-based batteries. In light of these merits, CBCBs hence arouse much attention from both industry and academia. In this review, we present chemical/mechanical characteristics of CBCBs and systematically discuss the recent advancements of cross-linked binders via chemical bonding for silicon-based electrodes. Focus is placed on the cross-linking chemistries, construction methods and structure–performance relationships of CBCBs. Finally, the future development and performance optimization of CBCBs are proposed. This discussion will provide good insight into the structural design of CBCBs for silicon-based electrodes.

For layered transition metal oxides cathode-based lithium batteries, the chemical degradation of electrolytes leads to fast battery capacity decay, severely challenging their practical applications. This kind of chemical degradation of electrolytes is caused by the oxidation of reactive oxygen (e.g., singlet oxygen) and the attack of free radicals during cycling. To address this, we first report a biologically inspired antiaging strategy of developing the photostabilizer with singlet oxygen- and free radicals-scavenging abilities as a cathode binder additive. It is fully evidenced that this binder system consisting of the binder additive and a commercially available polyvinylidene difluoride can scavenge singlet oxygen and free radicals generated during high-voltage cycling, thus significantly restraining electrolyte decomposition. As a result, high-voltage layered transition metal oxides-based lithium batteries with reproducibly superior electrochemical performance, even under elevated temperatures, can be achieved. This bioinspired strategy to scavenge reactive oxygen and free radicals heralds a new paradigm for manipulating the cathode/electrolyte interphase chemistry of various rechargeable batteries involving layered transition metal oxides-based cathodes.