Multifunctional semi-interpenetrating polymer network-nanoencapsulated cathode materials for high-performance lithium-ion batteries

Abstract

As a promising power source to boost up advent of next-generation ubiquitous era, high-energy density lithium-ion batteries with reliable electrochemical properties are urgently requested. Development of the advanced lithium ion-batteries, however, is staggering with thorny problems of performance deterioration and safety failures. This formidable challenge is highly concerned with electrochemical/thermal instability at electrode material-liquid electrolyte interface, in addition to structural/chemical deficiency of major cell components. Herein, as a new concept of surface engineering to address the abovementioned interfacial issue, multifunctional conformal nanoencapsulating layer based on semi-interpenetrating polymer network (semi-IPN) is presented. This unusual semi-IPN nanoencapsulating layer is composed of thermally-cured polyimide (PI) and polyvinyl pyrrolidone (PVP) bearing Lewis basic site. Owing to the combined effects of morphological uniqueness and chemical functionality (scavenging hydrofluoric acid that poses as a critical threat to trigger unwanted side reactions), the PI/PVP semi-IPN nanoencapsulated-cathode materials enable significant improvement in electrochemical performance and thermal stability of lithium-ion batteries.

A review on the stability and surface modification of layered transition-metal oxide cathodes

“…Besides the replacement reaction with coating materials to consume HF, Lewis basicity of some polymers has also been utilized to scavenge HF. Kim et al [76] developed a semiinterpenetrating polymer network (semi-IPN), which composes thermally stable cross-linked polyimide (PI) and polyvinylpyrrolidone (PVP), on the surface of LiCoO 2 (LCO) cathode materials. The PI/PVP coating layer exhibits significant HF-scavenging capability through the Lewis basic sites of pyrrolidone ring in PVP (Fig.…”

Functionalized Nanocellulose-Integrated Heterolayered Nanomats toward Smart Battery Separators

“…The pyrrolidone rings of PVP, enabled by their Lewis basicity, are known to effectively scavenge HF dissolved in the electrolyte solution . However, the bare PVP mat (without a PAN component) was chemically vulnerable to the electrolyte solution, resulting in the loss of its dimensional stability (Supporting Information, Figure S4a).…”

Facile Dual-Protection Layer and Advanced Electrolyte Enhancing Performances of Cobalt-free/Nickel-rich Cathodes in Lithium-Ion Batteries

“…Herein, to investigate the influence of protection for the NMT surface, we chose polyimide (PI) and polyvinyl pyrrolidone (PVP), as the coating materials to make a dual-polymer coating layer of PI/PVP (further abbreviated as PP in this work) on the NMT particle surface. The PP-coating layer has been reported to not only fabricate a uniform thin layer on the surface of the cathode active material but also alleviate side reactions between the cathode surface and electrolyte by its HF scavenging ability during the electrochemical performance . The thermally-cured PI is known as a stable polymer that does not contain any chemical functional groups which can cause the undesirable chemical and electrochemical reactions.…”

“…The PP-coating layer has been reported to not only fabricate a uniform thin layer on the surface of the cathode active material but also alleviate side reactions between the cathode surface and electrolyte by its HF scavenging ability during the electrochemical performance. 23 The thermally-cured PI is known as a stable polymer that does not contain any chemical functional groups which can cause the undesirable chemical and electrochemical reactions. The PVP was chosen and combined with PI as a functional polymer to adjust the polarity of the coating layer so as to form a more uniform coverage on the cathode surface.…”