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Silicon offers an extremely high theoretical specific capacity, but suffers from dramatic volume change during lithiation/delithiation processes, which typically leads to rapid anode degradation. Here we designed a facile and self-assembly strategy to construct a three-dimensional (3D) polymeric network as a promising binder for high-performance silicon submicro-particle (SiSMP) anodes through in situ interconnection of alginate chains by additive divalent cations. The highly cross-linked alginate network exhibits superb mechanical properties and strongly interacts with SiSMPs, which can tolerate the volume change of SiSMPs and restrict the volume expansion of the laminates to a large degree, thus effectively maintaining the mechanical and electrical integrity of the electrode and significantly improving the electrochemical performance. As a result, SiSMPs with a 3D binder network exhibit high reversible capacity, superior rate capability and much prolonged cycle life. Additionally, the 3D alginate binder was also successfully applied for the industrial submicro-silicon waste from solar cell production. With all of the advantages, the innovative way to tolerate the severe volume change by using a high-strength polymeric network may open a new approach to realize the industrial application of Si-based anodes in lithium-ion batteries.

and xueyongz@caas.net.cn). † These authors contributed equally to this work. SUMMARYThe physical map of the hexaploid wheat chromosome 3B was screened using centromeric DNA probes. A 1.1-Mb region showing the highest number of positive bacterial artificial chromosome (BAC) clones was fully sequenced and annotated, revealing that 96% of the DNA consisted of transposable elements, mainly long terminal repeat (LTR) retrotransposons (88%). Estimation of the insertion time of the transposable elements revealed that CRW (also called Cereba) and Quinta are the youngest elements at the centromeres of common wheat (Triticum spp.) and its diploid ancestors, with Quinta being younger than CRW in both diploid and hexaploid wheats. Chromatin immunoprecipitation experiments revealed that both CRW and Quinta families are targeted by the centromere-specific histone H3 variant CENH3. Immuno colocalization of retroelements and CENH3 antibody indicated that a higher proportion of Quinta than CRWs was associated with CENH3, although CRWs were more abundant. Long arrays of satellite repeats were also identified in the wheat centromere regions, but they lost the ability to bind with CENH3. In addition to transposons, two functional genes and one pseudogene were identified. The gene density in the centromere appeared to be between three and four times lower than the average gene density of chromosome 3B. Comparisons with related grasses also indicated a loss of microcollinearity in this region. Finally, comparison of centromeric sequences of Aegilops tauschii (DD), Triticum boeoticum (AA) and hexaploid wheat revealed that the centromeres in both the polyploids and diploids are still undergoing dynamic changes, and that the new CRWs and Quintas may have undertaken the core role in kinetochore formation.